Hedging and Pairs Trading

Hedging is a foundational concept in trading, encountered as soon as one begins engaging in the markets. It is the act of reducing, neutralizing, or even reversing ones exposure to a given instrument. Pairs trading is a structured form of hedged trading in which the objective, from inception, is to maintain exposure as close to market-neutral as possible.

There are multiple reasons and methods for implementing a hedge. Below we examine why and how traders use this technique.

Intraday vs. Long-Term Hedging

There are different situations in which a trader may decide to initiate a hedge:

• Intraday speculative positioning:

• Suppose you open an intraday speculative position and price moves against you. In this case, you may want to mitigate risk without immediately realizing a loss by triggering your stop loss on the primary trade.

• Medium- to long-term positioning:

• Alternatively, you may hold a position with a 2–3 month horizon. Even if your broader directional thesis remains intact, you anticipate countertrend moves during that period. In such cases, temporarily neutralizing exposure during adverse swings can help optimize overall profitability.

Hedging Instead of Using a Stop Loss

Assume you initiate an aggressive long position of +1,000 units at $100, targeting $100.65 (+0.65%) — Case A.

Instead of rising, price declines toward $99.90, which, according to your trading plan, could represent your stop-loss level. However, you observe that in previous sessions the market found support between $99.90 and $99.75. Rather than closing the position at $99.90, you open a short position of equal size (1,000 units), effectively neutralizing your exposure within that 15-cent range and preventing additional losses.

If price breaks below $99.75, you may then decide to close the entire structure.

In this way, the hedge acts as a temporary risk-freezing mechanism instead of a hard stop.

Hedging to Optimize a Long-Term Trade

Now consider buying 1 lot at $100 with a three-month target of $115.

Even if your macro thesis is correct, price will not move in a straight line. There will be pullbacks. For example, shorter-term indicators (e.g., a 30-minute chart showing overbought conditions) may suggest an imminent retracement. In that case, you could open a 1-lot short hedge, allowing momentum to reset before the next upward leg, thereby avoiding drawdown during the correction.

Full Hedge, Partial Hedge, or Reversal

For discretionary traders, the degree of hedging is often subjective.

A full hedge brings the position to flat exposure: long 100, short 100 — net zero risk.

However, execution can vary depending on the traders probability assessment of key levels.

Returning to Case A, suppose the $99.75–$99.90 range is considered a “noisy” area where price could stall unpredictably. You might hedge only 80% of the position at $99.90 (short 800 units), maintaining a residual long exposure of 200 units until $99.75. At that level, you could either close everything or even reverse the position.

Alternatively, if $99.75 represents a structural invalidation point for your strategy, you might wait for that level and sell 1,200 units — effectively reversing the position once your original thesis is invalidated.

Hedging is therefore an active risk management technique. It allows a trader to dynamically manage exposure around uncertain price zones and emphasize levels where conviction is lower.

What Instrument to Use for Hedging

The most straightforward hedge is executed on the same instrument.

For example, if you are long 1 lot of US500 and wish to hedge, the natural action is to sell 1 lot of US500.

However, correlated instruments may also serve as viable hedging vehicles. These may belong to the same sector, country, or asset class. For example, instead of shorting 1 lot of US500, one might hedge with US30.

Two key factors must be considered:

1. Absolute Price Level

If US500 trades at 6,950 and US30 at 50,300, the notional equivalence differs.

A rough ratio (6,950 / 50,300 ≈ 0.14) suggests that 0.14 lots of US30 would be required to approximate the exposure of 1 lot of US500.

2. Correlation and Beta

Correlation strength matters. You may observe that when US500 moves +0.5%, US100 moves +0.9%, or when EURUSD rises +0.20%, AUDUSD rises +0.35%.

The rigorous approach involves running a regression on returns and calculating the hedge ratio (beta). A more approximate method involves analyzing historical price behavior over the relevant time sample.

This type of cross-instrument hedge is inherently imperfect and rarely produces full neutrality. However, it can be used strategically to exploit relative strength dynamics.

Pairs Trading

Pairs trading resembles the cross-hedging approach described above, but with a crucial difference: it is not a defensive adjustment to a primary trade — it is the strategy itself.

Technically, to validate a pairs trade, one should test for cointegration between the two historical price series.