A pairs trade is the cleanest way to express a view about which asset wins rather than which way the market goes. You go long one asset and short a related one, so the broad-market direction the two share largely cancels out, and what remains is the spread between them. On Legend you can build pairs across crypto, stocks, commodities, and FX in one self-custody account, because every market is a perp you can go long or short. This is the pillar guide to relative value; the gold-silver ratio post is the worked example to read alongside it.
The Thesis
Every asset price contains two things: the broad move of its market, and its own performance relative to peers. An outright long mixes both. A pairs trade strips out the first and isolates the second. By going long the asset you expect to outperform and short a related one you expect to lag, a rally or selloff that lifts or sinks both largely offsets — leaving your call on relative performance. This is the relative-value structure behind the whole thesis-trade framework.
How to Build a Pair on Legend
You always put on two legs, in opposite directions, on related assets. A few examples using live perps:
- NVDA vs a lagging chipmaker — long the leader you think keeps winning, short the one you expect to fall behind, to isolate who wins AI silicon.
- COIN vs MSTR — long one crypto-equity, short the other, to trade their relative crypto beta instead of crypto's direction.
- COPPER vs GOLD — long the industrial metal, short the safe-haven metal, to express a growth-versus-risk-off view. (Reverse it to bet the other way.)
- GOLD vs SILVER — the canonical precious-metals ratio trade, covered in full in the gold-silver ratio guide.
In each case you choose a direction for the spread and set both legs at once.
Start trading on Legend to set both legs in one account.
Balancing the Legs by Notional
This is the step beginners skip, and it decides whether you are actually trading the spread. A pair only isolates relative value if the two legs are notional-balanced — roughly equal dollar exposure on each side.
If you put $5,000 long COPPER and only $2,000 short GOLD, you are not trading the spread — you are mostly long copper with a small hedge. To trade the relationship cleanly, match the notional: about $5,000 long COPPER against about $5,000 short GOLD. Then a broad metals rally or selloff largely cancels, and what remains is the copper-versus-gold call you actually hold. Balance by dollar notional, not by number of contracts or by margin posted.
Why Relative Value Reduces Broad-Market Direction
Because the legs point in opposite directions on correlated assets, the part of each move that comes from the shared market mostly nets out. A long-only NVDA position loses in a tech-wide selloff even if NVDA is the strongest name; a balanced long-NVDA / short-laggard pair can still profit, because NVDA falls less than the name you shorted. That is the appeal: a pair targets the spread and dampens the market beta you did not want.
Funding on Both Legs
A pair is two perps, so you pay or receive funding on each side. The net of the two is your carry. A wide funding differential is a real cost on a spread you may hold for weeks, and it can quietly erode a winning position — always check funding on both legs before sizing, and factor the net into the trade.
Sizing and Risk
- Size the pair, not each leg. Decide the max loss for the combined position and balance the legs to it. See how to manage risk.
- Use isolated margin. Cap the downside so an unexpected divergence cannot bleed into the rest of the account — compare cross vs isolated margin.
- Lower leverage than an outright. A balanced spread is calmer, which tempts traders to crank leverage — resist it.
- Re-balance as prices move. Legs drift out of balance as the assets move; check the notional split periodically.
What Could Go Wrong
A spread can stay stretched far longer than you expect, and "cheap relative to history" is not a timing signal. The pair loses if the wrong leg outperforms — long COPPER / short GOLD loses in a risk-off where gold leads. Funding can erode a winning spread over a long hold, and badly unbalanced legs leave hidden directional risk on the whole complex. Size and balance accordingly.
This article is educational and is not financial advice.