What is Swap in Forex? A Complete Guide for Mexico Traders (2026)

What Exactly is a Forex Swap?

A forex swap, also called rollover, is the interest rate differential between the two currencies in a pair, applied when you keep a trade open past 5:00 PM New York time (4:00 PM Mexico City time). If the currency you bought has a higher interest rate than the one you sold, you receive a positive swap (credit). If the opposite, you pay a negative swap (debit).

How Swap Works for Mexico Traders

Mexico traders often trade USD/MXN, EUR/USD, or GBP/USD. The swap rate depends on central bank rates: the Federal Reserve (US) and Banco de México (Mexico). As of 2026, Mexico's interest rate is typically higher than the US rate (e.g., 10% vs 5%). So, if you buy USD/MXN (buy USD, sell MXN), you pay the higher MXN rate and earn the lower USD rate—resulting in a negative swap. Conversely, selling USD/MXN (sell USD, buy MXN) earns you a positive swap because you hold the higher-yielding peso.

Practical Example for Mexico Traders

Suppose you open a 1 standard lot (100,000 units) short USD/MXN position at 20.00. The USD interest rate is 5%, MXN is 10%. The swap calculation: (100,000 × (0.05 - 0.10) / 365) = approximately -13.70 USD per night. You pay $13.70 daily to hold this position. Over a week, that's nearly $96 in costs. For a long USD/MXN trade, you would earn a positive swap, but the trade direction matters.

Why Swap Matters for Mexico Retail Traders

Many Mexico traders use leverage up to 1:30 (as per local financial authority rules). High leverage amplifies swap costs because you're controlling larger positions with less capital. A $1,000 account trading 1 lot USD/MXN could face swap charges that wipe out profits quickly. Additionally, swap rates are often higher for exotic pairs involving MXN due to volatility and liquidity premiums. Always check your broker's swap rates in the contract specifications before entering a trade.

For Mexico traders, swap is particularly relevant because of the high interest rate differential between the Mexican peso and major currencies like the USD, EUR, or JPY. This means carry trade strategies—where you earn positive swap by selling low-yielding currencies and buying high-yielding ones—can be profitable. However, the local financial authority (CNBV) requires brokers to clearly disclose swap rates, so always verify them. When funding your account via Bank Transfer or Skrill in USD, swap charges are deducted directly from your USD balance. Some brokers also accept USDT deposits, which can help you avoid currency conversion fees but swap still applies in USD terms. Mexico traders should also note that swap rates are typically quoted in points per lot and can vary between brokers offering the same pair. Always compare swap rates when choosing a broker, especially if you plan to hold positions for more than a day.

1. Check Your Broker's Swap Rates
   Log into your broker's platform (e.g., MetaTrader 4 or 5) and navigate to Market Watch. Right-click on the pair (e.g., USD/MXN) and select 'Specifications' to see long and short swap rates in pips or points. For Mexico traders, note that swap rates are often listed in USD per lot.
2. Determine Your Trade Direction
   If you plan to hold a position overnight, decide whether you want to earn or pay swap. For USD/MXN, selling (short) earns positive swap because MXN has higher interest. Buying (long) pays negative swap. Align your strategy accordingly.
3. Calculate Daily Swap Cost
   Multiply your position size in lots by the swap rate. For example, if swap short is +15 USD per lot and you hold 0.5 lots, you earn $7.50 per night. Use a swap calculator or manual formula: (lots × swap rate in points × pip value).
4. Plan for Triple Swap Wednesday
   On Wednesday nights, swap is charged or credited for three days (Wed, Thu, Fri). This means your cost or profit is tripled. Mexico traders should avoid holding positions through Wednesday unless the swap is favorable and you can absorb the risk.

Swap is often compared to the 'carry trade' in forex. A carry trade involves buying a currency with a high interest rate and selling one with a low rate to earn the swap. For Mexico traders, this typically means selling USD/MXN (since MXN has higher rates) or selling EUR/MXN. Swap is different from the spread because it recurs daily, while the spread is a one-time cost. Also, swap is not the same as commission—commissions are fixed per trade, while swap varies with interest rates and position size. For long-term Mexico traders, swap can be a significant source of income or expense, so it's crucial to understand the difference and plan accordingly.

Swap works by applying the interest rate differential between the two currencies in a forex pair. For Mexico traders trading USD/MXN, the process is straightforward: at 5:00 PM New York time (4:00 PM Mexico City time), your broker automatically closes and reopens your position at the same price, applying a credit or debit based on the interest rate difference. For example, if you hold a short USD/MXN position (sell USD, buy MXN), you earn interest on the MXN you bought and pay interest on the USD you sold. Since Mexico's interest rate is typically higher than the US rate, you receive a positive swap. The exact amount depends on your position size and the broker's markup. Most brokers display swap rates in points per lot in the platform's market watch window.

Example 1: Short USD/MXN (Earning Swap)
You sell 1 lot of USD/MXN at 20.00. Broker swap rate for short is +15 USD per lot per day. You hold for 5 days (excluding Wednesday triple). Total swap earned: 5 × $15 = $75. This is added to your account balance in USD.

Example 2: Long USD/MXN (Paying Swap)
You buy 1 lot of USD/MXN at 20.00. Broker swap rate for long is -12 USD per lot per day. You hold for 3 days. Total swap cost: 3 × $12 = $36. This is deducted from your USD balance. If your account has $500, this is a 7.2% loss in just 3 days.

Example 3: Triple Swap Wednesday
If you hold a short USD/MXN position through Wednesday, the swap is tripled: 3 × $15 = $45 for that night. Always check the day before holding through Wednesday.

The local financial authority in Mexico, the Comisión Nacional Bancaria y de Valores (CNBV), regulates forex brokers that offer services to Mexican residents. While the CNBV does not directly set swap rates, it requires brokers to disclose all fees, including swap, in a transparent manner. Brokers must also adhere to leverage limits (1:30 for retail) and ensure fair trading conditions. Mexico traders should verify that their broker is registered with the CNBV or holds a license from a reputable international regulator. This regulatory oversight helps prevent unfair swap manipulation and ensures you can dispute any discrepancies. Always check the 'Regulation' section of your broker's website to confirm their status.

• Monitor Central Bank Rates: Follow announcements from Banco de México and the US Federal Reserve. Rate changes directly impact swap rates for USD/MXN and other pairs.
• Use Swap-Free Accounts Wisely: If you qualify for a swap-free (Islamic) account, you can avoid overnight charges, but ensure your broker doesn't impose hidden fees.
• Close Before 4:00 PM Mexico City Time: To avoid swap, close all positions before the rollover time (5:00 PM New York / 4:00 PM Mexico City). Day trading eliminates swap.
• Compare Brokers: Swap rates vary between brokers. For example, one broker may offer +20 USD for short USD/MXN while another offers +15 USD. Choose the best for your strategy.
• Factor Swap into Risk Management: If you hold positions for weeks, swap costs can exceed spreads. Include swap in your stop-loss and take-profit calculations.

Understanding swap is essential for any Mexico trader who holds positions overnight. By knowing how swap is calculated, when it applies, and how to manage it, you can reduce costs and even earn extra income from positive swap. Start by checking swap rates for your favorite pairs like USD/MXN, and consider strategies like carry trades if the rates are favorable. Use a demo account to practice swap management without risking real capital. Finally, choose a broker regulated by the local financial authority and compare swap rates before depositing via Bank Transfer, Skrill, or USDT. For more educational resources, explore our other guides on forex trading in Mexico.