Forex trading is a fast-paced and exciting endeavor. However, it’s one that requires careful thought and attention to avoid losses. While the potential for gains is high with the correct strategy, there is much more to it than simply choosing the right move. Leverage is a powerful tool for traders as it can amplify any potential profits. Yet, it doesn’t come without risk. Therefore it’s vital to choose a broker that not only suits specific goals but also provides enough leverage to make the trade worthwhile.
There are many high leverage forex brokers on the market and they offer different leverage ratios. The average leverage ratio is 1:500, however there are brokers that offer much higher rates, up to 1:3000 in some cases. While that may sound impressive, with a higher chance of gains, it also means an increased chance of losses.
In this guide, I will talk about eight of the highest leverage forex brokers on the market. I’ll discuss their pros and cons, features, and vital points. Ultimately, it will be easier to make an informed decision that leads to sensible yet profitable trades.
RoboForex offers the highest leverage at 1:2000 with a user-friendly platform.
FXTM provides excellent educational resources and competitive pricing.
AvaTrade stands out for its variety of trading platforms and strong regulation.
Exness offers ultra-low spreads and high leverage up to 1:2000.
FBS provides the highest leverage in the industry at 1:3000.
NordFX offers high leverage and cryptocurrency trading options.
InstaForex provides flexible account options and high leverage up to 1:1000.
FXOpen is known for its ECN trading and competitive pricing structure.
Comparison Table
Broker
Max Leverage
Min Deposit
Regulation
Platforms
RoboForex
1:2000
$10
FSC Belize
MT4, MT5, R StocksTrader
FXTM
1:2000
$200
FCA, CySEC
MT4, MT5, FXTM Trader
AvaTrade
1:400
$100
Central Bank of Ireland, ASIC
MT4, MT5, AvaTradeGO
Exness
1:2000
$1
FCA, CySEC
MT4, MT5, Exness Trader
FBS
1:3000
$5
CySEC, ASIC
MT4, MT5, FBS Trader
NordFX
1:1000
$10
Vanuatu FSC
MT4, MT5
InstaForex
1:1000
$1
CySEC
MT4, MT5, InstaTrader
FXOpen
1:500
$100
FCA, ASIC
MT4, MT5, TickTrader
Criteria Breakdown Summary
To fully assess the highest leverage forex brokers, I created a set of criteria to measure each one. My criteria included regulatory compliance, maximum leverage, risk management tools, markets, trading platforms, spreads and commissions, educational resources, and customer support. I also checked user and industry expert reviews. I then scored each of the high leverage forex brokers out of 5 for each criterion, giving a full picture of each.
Roboforex
Best Known for Unparalleled Leverage
The first high leverage broker I reviewed was Roboforex. This broker was established in 2009 and is a popular choice for high leverage options. It has a maximum leverage of 1:2000, and offers a range of account types for different experience and trading styles. A potential downside is that the FSC (Financial SErvices Commission) of Belize regulates Roboforex. While still giving some protection, it doesn’t provide as much as a top-tier regulator.
Roboforex is a high leverage broker with 15 years experience. Source: Roboforex
Key Features
Roboforex has many features to enhance the trading experience. Several trading platforms are available, including MetaTrader 4 & 5, and the proprietary platform, R StockTrader. There are also several account types on offer, and these have different leverage options and trading conditions attached to them.
Additionally, this broker has a copy trading system (CopyFX), which is a quality feature for less experienced traders in particular. This allows traders to copy successful past trades and potentially replicate their success.
Pros
High maximum leverage of 1:2000
Diverse range of trading platforms and account types
Low minimum deposit requirements
Competitive spreads and commissions
Cons
Regulated by a less stringent offshore authority
Limited educational resources compared to some competitors
Higher commissions for some account types
Criteria Evaluation
Regulation: 4/5
Maximum leverage: 5/5
Risk management tools: 4/5
Trading platforms: 4/5
Range of markets: 4/5
Spreads and commissions: 3/5
Customer support: 4/5
Educational resources: 3/5
Community Reviews and Expert Recommendations
Overall, Roboforex receives positive reviews. Many users praise the high leverage options, along with the platforms on offer. Some users mention slow withdrawal processing times, but this is an isolated issue.
“I’ve been using this broker for a while now (4 Years), and they’re honestly the best I’ve come across. Their customer support is top-notch – always quick to help and super knowledgeable. What I love most is the speedy withdrawals for bank transfers, usually processed in under 12 hours. Electronic Payouts are even faster. The trading conditions are fantastic too – tight spreads, low commissions and fast executing. Overall, this broker makes trading a breeze. Can’t recommend them enough!” – Johannes Pichler via Trustpilot
“So far, very impressed – using this as my first forex broker and whilst I was initially worried about the offshore-nature of this Forex broker, the level of service and site has been amazing as well as bonuses and other account features. I started with a Procent account, and now using an ECN account with larger amounts. Not withdrawn any cash yet, waiting for a free day to see how it works out, but if that is smooth I’ll certainly update this review to a 5-star.” – Dan Clark via Trustpilot
Industry experts recommend Roboforex for intermediate and experienced traders. They feel the high leverage may not be suitable for beginners. Our Roboforex review provides more details.
Pricing
RoboForex offers competitive pricing with spreads starting from 0 pips on ECN accounts. Commission charges vary depending on the account type, with some accounts featuring commission-free trading. The minimum deposit is as low as $10 for certain account types, making it accessible to traders with varying capital.
FXTM
Best Known for Educational Excellence
FXTM, also known as Forextime, is one of the most popular regulated forex brokers with high leverage. It is regulated by CySEC and FCA for peace of mind, and offers leverage up to 1:2000. As a result, it is a good choice for traders seeking the highest leverage.
This broker offers advanced risk management features, including negative balance protection. It also has a tiered loyalty program offering enhanced trading conditions over time.
FXTM offers high leverage ratios and excellent regulatory oversight. Source: FXTM
Key Features
FXTM is a high-quality broker offering excellent educational resources. This includes video tutorials, webinars, and in-depth articles. As such, it’s a good choice for beginners who want to move slowly in the world of high leverage trading. Additionally, there are several account types to suit different needs, including a standard account and ECN options. Other stand-out features include the Pivot Points strategy tool, which is a technical analysis indicator, along with FXTM Invest for copy trading.
Pros
Excellent educational resources for all trader levels
Strong regulatory oversight from reputable authorities
Competitive pricing with low spreads on some account types
Innovative trading tools and features
Cons
Higher minimum deposits for some account types
Limited cryptocurrency offerings compared to some competitors
Inactivity fees may apply to dormant accounts
Criteria Evaluation
Regulation: 5/5
Maximum leverage: 5/5
Risk management tools: 4/5
Trading platforms: 4/5
Range of markets: 4/5
Spreads and commissions: 4/5
Customer support: 4/5
Educational resources: 5/5
Community Reviews and Expert Recommendations
FXTM receives mostly positive feedback from the trading community. Most particularly appreciate the large range of educational resources, along with the user-friendly platforms. Many traders also mention the range of account types and competitive spreads on ECN accounts.
“Very good experience. Customer support is also best as compared to other brokers. Deposit/withdrawals were processed very fast.” – Amit Kalamkar via Trustpilot
“FXTM is the first and the best broker I’ve ever traded with. Deposit and withdrawals are easy and fast, they also give educational content on technical and fundamental analysis for the week ahead, exchange rate is also relatively favorable, their customer service is also top notch. There has been no issue with them at all since I opened a trading account with them. Kudos to them!!” – Adeola via Trustpilot
Industry experts praise FXTM for its educational focus and the range of innovative features, such as copy trading and technical analysis. They also emphasize top-tier regulatory oversight.
Pricing
FXTM offers competitive pricing with spreads from 0.1 pips on ECN accounts. Standard accounts feature no commission charges, while ECN accounts have a small commission per lot traded. Minimum deposits vary by account type.
AvaTrade
Best Known for Platform Variety
AvaTrade is one of the most reputable forex brokers with high leverage, having been established in 2006. There are many trading platforms available, along with maximum leverage of 1:400. While this is lower than some of its competitors, it is a good choice for beginners and intermediate traders. Additionally, AvaTrade has strong regulation and several innovative features.
AvaTrade is a broker with medium leverage and a range of tradable instruments.Source: AvaTrade
Key Features
While AvaTrade doesn’t offer the highest leverage on the market, it is an excellent choice for beginner traders. There are many trading platforms, including MetaTrader 4 & 5, along with the proprietaryAvaTradeGO app. The web-based AvaOptios is available for options trading. In addition, there are many tradable instruments, including forex, cryptocurrencies, CFDs on stocks, and commodities.
A key feature is AvaProtect, which insures trading positions against losses. There is a small fee, but this is minimal for the protection it gives.
Pros
Wide range of trading platforms and tools
Strong regulatory oversight from multiple authorities
Innovative features like AvaProtect
Excellent educational resources and market analysis
Cons
Lower maximum leverage compared to some competitors
Inactivity fees may apply to dormant accounts
Limited cryptocurrency offerings
Criteria Evaluation
Regulation: 5/5
Maximum leverage: 4/5
Risk management tools: 5/5
Trading platforms: 5/5
Range of markets: 5/5
Spreads and commissions: 4/5
Customer support: 4/5
Educational resources: 5/5
Community Reviews and Expert Recommendations
Overall, AvaTrade receives positive praise from traders. Most users appreciate the range of platforms and account types on offer. They also highlight educational resources and AvaProtect functionality. However, some users would prefer higher leverage ratios.
“AvaTrade company has got all the tools needed for everyone who wants to start trading, providing educational and efficient trading platforms as well as many other helpful services.” – Maan Yassin via Trustpilot
“My experience with Avatrade, and especially Mark Mates, is incredibly positive. Both he and their technical support are always quick to respond with thoughtful and competent answers. If there are any problems with withdrawals, they are also incredibly helpful. Only recommendations from here.” – Peter F via Trustpilot
Industry experts praise AvaTrade’s strong regulatory oversight and its range of innovative features. Our AvaTrade review gives more details.
Pricing
AvaTrade offers competitive spreads from 0.9 pips on major forex pairs. The broker doesn’t charge commissions on most trades, instead making money from the spread. Minimum deposits start at $100, which is relatively low compared to some competitors.
Exness
Best Known for Ultra-Low Spreads
Exness is a popular broker that was founded in 2008. It has gained notoriety amongst traders looking for the best high leverage brokers, offering ratios up to 1:2000. Additionally, Exness has excellent regulatory oversight, along with a range of features to enhance the overall experience. Their social trading platform is particularly useful for copy traders, along with risk management features, such as negative account balance protection.
Exness offers leverage of up to 1:2000, amongst the highest on the market. Source: Exness
Key Features
Exness offers ultra-lw spreads at 0 pips on some account types, of which there are several. The social trading platform is a standout feature, allowing raiders to copy successful trades performed in the past. Additionally, the Exness Trader app is an ideal option for on-the-go trading.
This broker offers a VPs hosting service for automated trading strategies along with many tradable instruments.
Pros
Ultra-low spreads starting from 0 pips
High maximum leverage of 1:2000
Fast withdrawal processing times
User-friendly proprietary trading app
Cons
Limited range of tradable assets compared to some competitors
Educational resources could be more comprehensive
Some account types have high minimum deposit requirements
Criteria Evaluation
Regulation: 4/5
Maximum leverage: 5/5
Risk management tools: 4/5
Trading platforms: 4/5
Range of markets: 4/5
Spreads and commissions: 5/5
Customer support: 4/5
Educational resources: 3/5
Community Reviews and Expert Recommendations
Exness receives positive feedback from users, especially regarding its low spreads and fast execution speeds. High leverage options are another highlight, along with fast withdrawal processing. Many users also enjoy the copy trading function. However, some users believe the educational resources could be expanded.
“The broker is so good. There is availability of tools and indicators, and it’s easy to use. I am so satisfied with the app.”Abraham via Trustpilot
“Great app for traders. I have experience of 2-3 years of working with EXNESS, and it is the best. Easy deposits and withdrawals.” – Kamaldeep via Trustpilot
Industry experts recommend Exness for beginner and advanced traders alike. They particularly mention its strong regulatory status and competitive trading conditions.
Pricing
Exness offers highly competitive pricing with spreads starting from 0 pips on ECN accounts. Commission charges apply to some account types, but these are generally low. Minimum deposits vary by account type, starting from as low as $1 for Standard accounts.
FBS
Best Known for Extreme Leverage
Traders seeking the highest leverage ratios in the industry will enjoy FBS. This broker was established in 2009, giving it over a decade of experience. It offers leverage up to 1:3000, which is what sets it apart from other similar brokers. Additionally, FBS is well-regulated, with oversight by CySEC and ASIC.
FBS is a high leverage broker, with ratios up to 1:3000. Source: FBS
Key Features
FBS has many features to add to its appeal, including several account types for different trading styles. Additionally, there are many tradable instruments on offer, including forex, CFDs on stock, commodities, and cryptocurrencies. A key standout feature is the low minimum requirements, just $1 for certain account types.
Alongside its excellent trading conditions, this broker also has a wide range of educational resources.
Pros
Highest leverage in the industry at 1:3000
Very low minimum deposit requirements
Comprehensive educational resources
Regular promotions and trading contests
Cons
Extreme leverage can be very risky for inexperienced traders
Limited range of tradable assets compared to some competitors
Customer support quality can be inconsistent
Criteria Evaluation
Regulation: 4/5
Maximum leverage: 5/5
Risk management tools: 4/5
Trading platforms: 4/5
Range of markets: 4/5
Spreads and commissions: 4/5
Customer support: 3/5
Educational resources: 4/5
Community Reviews and Expert Recommendations
FBS receives mixed feedback from users. Most users appreciate high leverage and low minimum deposits. However, some users mention that customer support is slow at times.
“FBS is so great that they send me email updates about everything.. most of all, withdrawal and deposit requests were always on time, safe and no hassle.” – Alva Charisse De Los Reyes Gav via Trustpilot
“I have had my accounts with FBS for over 7 years and I have very good experiences. Very fast deposits and withdrawals. Their support is very good too even though some issues take time for them to investigate but they resolved all my issues.” – Kiki Si via Trustpilot
Industry experts recommend FBS for traders who appreciate high leverage ratios, however they advise caution due to the increased risk. As a result, they do not recommend this type of trading for less experienced individuals. Our FBS review provides more information.
Pricing
FBS offers competitive spreads from 0.1 pips on ECN accounts. Standard accounts feature no commission charges, while ECN accounts have a small commission per lot traded. The minimum deposit can be as low as $5 for Cent accounts.
NordFX
Best Known for Crypto-Forex Blend
NordFX is a reputable broker that has been around since 2008. It is renowned for its high leverage trading and strong cryptocurrency offerings. With leverage ratios up to 1:1000, this broker offers high levels but not the most substantial around, which is less risky overall. However, the Vanuatu Financial Services Commission, which may not give as much protection as some top-tier entities, regulates NordFX.
NordFX is a high leverage broker with a global presence. Source: NordFX
Key Features
NordFX has a range of features, including high leverage forex trading and excellent cryptocurrency options. There are many account types on offer, including a specific cryptocurrency account. This broker also offers social trading through the RAMM (Risk Allocation Management Model) system, along with a range of tradable assets. These include forex, stocks, cryptocurrencies, and indices.
Additionally, NordFX offers a VPS service for automated trading strategies and PAMM accounts.
Pros
High leverage options up to 1:1000
Strong focus on cryptocurrency trading
Low minimum deposit requirements
Social trading options through RAMM system
Cons
Regulated by a less stringent offshore authority
Limited educational resources compared to some competitors
Customer support can be slow at times
Criteria Evaluation
Regulation: 3/5
Maximum leverage: 5/5
Risk management tools: 3/5
Trading platforms: 4/5
Range of markets: 4/5
Spreads and commissions: 4/5
Customer support: 3/5
Educational resources: 3/5
Community Reviews and Expert Recommendations
NordFX receives a mix of positive and negative reviews from the trading community. Many users appreciate the high leverage options, along with the cryptocurrency account. The RAMM social trading system is also highlighted. However, some traders express concern over this broker’s offshore regulatory status.
“NordFx is a name synonymous with trust and transparency. I was always paid promptly from the moment I made profit. I have been a privileged trader of NordFx since 2014.” – Yash via Trustpilot
“Working with them for over a year now. When it comes to trading with a broker, our main priority is fast deposit and withdrawal as well as reasonable spreads along with support. Everything is perfect with NordFX. Now they provide withdrawal within 2 hrs via their new USDT option. That’s a huge advantage for a trader like me. Also, their support team is very helpful with everything. Their replies are fast and if we have an issue, they will solve it in a short period of time. I really enjoy working with them. Good broker. Looking forward to introducing my friends as well.” – Himash Kavinda via Trustpilot
Industry experts praise NordFX’s range of account types and tradable instruments. However, they advise caution when using high leverage trading. Our NordFX review gives more details.
Pricing
NordFX offers competitive spreads from 0.9 pips on standard accounts. Pro accounts feature lower spreads but include a commission per lot traded. The minimum deposit is as low as $10 for standard accounts, making it accessible to traders with varying capital.
InstaForex
Best Known for Flexible Trading Options
InstaForex is a reputable high leverage forex broker that was established in 2007. There are a range of account types on offer, to suit varying trading needs. Additionally, InstaForex offers leverage up to 1:1000. For extra peace of mind, this broker is regulated by CySEC, and provides negative balance protection and segregated client funds.
InstaForex is a high leverage forex broker that was established in 2007.Source: InstaForex
Key Features
InstaForex has many standout features, including a range of trading instruments, such as forex, cryptocurrencies, CFDs on stocks, and commodities. There are also several account types, including standard accounts and ECN options. The ForexCopy system is a highlight, which caters for copy traders who want to emulate successful trades.
Additionally, there are many promotions and bonuses over time, a VPS service for automated trading strategies, and PAMM accounts.
Pros
High leverage options up to 1:1000
Wide range of account types and trading instruments
Social trading through ForexCopy system
Regular promotions and bonuses
Cons
Spreads can be wider than some competitors
Educational resources could be more comprehensive
Some traders report issues with withdrawal processing times
Criteria Evaluation
Regulation: 4/5
Maximum leverage: 5/5
Risk management tools: 3/5
Trading platforms: 4/5
Range of markets: 4/5
Spreads and commissions: 3/5
Customer support: 3/5
Educational resources: 3/5
Community Reviews and Expert Recommendations
InstaForex receives a mix of positive and negative feedback from users. Most appreciate the flexible trading conditions, especially the range of account types. Additionally, the ForexCopy system receives high praise, alongside the regular promotional offers. However, some users mention delays with withdrawal processing times and occasionally slow customer support responsiveness.
“I have been a client of InstaForex since 2011. I’ve never had any problems with this broker, excellent bonus program but only one thing: they have to reduce their spreads for gold, silver, and crude oil like their competitors, icmarket exness etc. And start rewards/cash back programs for clients who come directly without IB.” – Najeeb Uddin Hashmi Adv via Trustpilot
“Great withdrawals and I usually get calls concerning customer service, so they check out my experience and update me on anything new.” – Kabelo Ratlhogo via Trustpilot
Industry experts recommend InstaForex for high leverage trading and praise the range of features. They also mention this broker’s strong regulatory oversight. Read our InstaForex review for details.
Pricing
InstaForex offers variable spreads from 3 pips on standard accounts. ECN accounts feature lower spreads but include a commission per lot traded. The minimum deposit varies by account type, starting from $1 for cent accounts, making it highly accessible to new traders.
FXOpen
Best Known for ECN Trading
The final highest leverage forex broker I reviewed was FXOpen. This broker was founded in 2003, so has years of experience. It is known for its ECN services, giving direct access to interbank liquidity. This broker offers leverage up to 1:500, which is lower than some of the other brokers I have reviewed but it is still a substantial amount.
FXOpen is regulated by the FCA and ASIC, giving a strong level of regulatory oversight for peace of mind.
FXOpen offers leverage up to 1:500 and is known for ECN trading. Source: FXOpen
Key Features
FXOpen specializes in ECN trading, with tight spreads and fast execution speeds. Additionally, there are many account types available aside from ECN accounts, so it’s a broker that caters to different needs. There are many tradable instruments available, including forex, indices, commodities, cryptocurrencies, and CFDs on stocks.
The MetaTrader 4 & 5 platforms are available, alongside the proprietary TickTrader platform. Experience traders will appreciate the PAMM and MAMM accounts, along with advanced charting and analysis tools.
Pros
True ECN trading conditions with tight spreads
Strong regulatory oversight from reputable authorities
Wide range of tradable assets
Innovative TickTrader platform
Cons
Lower maximum leverage compared to some competitors
Higher minimum deposits for some account types
Educational resources could be more comprehensive
Criteria Evaluation
Regulation: 5/5
Maximum leverage: 4/5
Risk management tools: 4/5
Trading platforms: 4/5
Range of markets: 4/5
Spreads and commissions: 5/5
Customer support: 3/5
Educational resources: 3/5
Community Reviews and Expert Recommendations
Overall, FXOpen receives positive reviews from users, with most praising the ECN trading conditions. The range of tradable assets is also mentioned in positive terms, along with the TickTrader platform. However, some users would prefer a wider range of educational resources.
“I have been working with this company for over 10 years. And during all this time, I have not had a reason to regret it. Apparently, this is one of the best companies in this area. I can judge this based on my personal experience.” – Sergey Klimov via Trustpilot
“I’ve been trading with FxOpen for more than ten years. It is the best forex dealer that I know of. I never encountered any issue with FxOpen.” – Lim Eng Beng via Trustpilot
Industry experts recommend FXOpen for intermediate and experienced traders, and highlight its strong regulation. Read our FXOpen review for details.
Pricing
FXOpen offers competitive pricing with spreads starting from 0 pips on ECN accounts. Commission charges apply to ECN accounts, typically around $1.5 per lot round turn. Minimum deposits vary by account type, starting from $100 for standard accounts.
Notable Mentions
IG Group
IG Group is a well-established broker that has a range of tradable assets and strong regulatory oversight. This broker doesn’t offer the highest leverage but it has a reliable and well-rounded trading environment.
Saxo Bank
Saxo Bank is well-known for its excellent trading platforms and research features. This broker is suitable for experienced traders and offers access to a wide range of global markets.
Swissquote
Swissquote offers a wide range of tradable instruments and services. It is known for its strong banking background and countless trading solutions.
XTB
XTB is a recognized global broker that has a user-friendly platform and a focus on educational resources. It has competitive trading conditions and a proprietary trading platform.
Frequently Asked Questions
What is leverage in forex trading?
Leverage in forex trading is a tool that can be used to amplify gains. However, it can also amplify losses. It allows traders to control larger positions with smaller amounts of capital, and is expressed as a ratio, such as 1:1000. In this example, for every $1, you control $100 in the market.
How do I choose the right leverage level for my trading?
To choose the right leverage level, you must first think about your trading experience, strategy, and your risk tolerance. If you’re a beginner trader, start with lower leverage and then increase slowly as you become more experienced. It’s also important to think about the volatility of the instruments you’re trading.
Are high-leverage forex brokers safe?
Every type of trading comes with a certain amount of risk. However, if you choose a high leverage forex broker with solid regulation and good reviews, the risk is reduced. It’s also vital to take your time and understand the risks involved in high-leverage trading.
What are the risks of trading with high leverage?
High-leverage trading can amplify gains, but it can also increase your losses. The main risks include large losses, stress, potential for negative balance, and a higher chance of margin calls and forced liquidations.
How do regulatory restrictions affect leverage offerings?
Regulatory leverage restrictions vary by jurisdiction. In Europe, ESMA regulations limit retail trader leverage to 1:30 for major forex pairs. Similar restrictions exist in the UK and Australia. However, offshore regulators sometimes allow higher leverage levels, which is a key reason why some brokers operate under several regulatory licenses.
Final Thoughts
I have reviewed eight of the highest leverage forex brokers on the market and it’s clear that they all have their pros and cons. There is no perfect fit for everyone, so it’s vital to assess your trading experience, goals, strategy, and risk tolerance.
Leverage allows you to control large large positions with a small amount of capital, and this is certainly tempting. However, it’s important to remember that high-leverage trading carries significant risks. Understanding the market and making careful decisions is vital.
It’s a good idea to prioritize brokers with strong regulatory oversight, even if they do have lower leverage ratios. You should also regularly review and adjust your leverage based on market conditions and your trading performance. By making careful moves, you reduce your overall risk level.
Additionally, learning more about trading, even if you’re already experienced, is a positive step. Here at Top Brokers, we’re committed to helping traders just like you learn as much as possible about the trading world. By doing this, you reduce your chances of significant losses because you can make informed decisions. We have a range of resources to help, including how to read forex charts for beginners, and how to create and manage a forex trading strategy. Ultimately, successful trading is not leverage. Finding the right broker is the best strategy to help you in your trading goals. Additionally, managing forex trading stress will enable you to see market conditions more clearly, especially in high-leverage situations.
United StatesUS