What Is Lot Size?
Lot size refers to the standardized quantity of an asset in a single trade unit. In crypto futures, one lot might represent 1 BTC, 0.01 BTC, or 100 USD worth of the asset, depending on the exchange. Spot markets typically have minimum order sizes denominated in the base currency (e.g., 0.0001 BTC).
How Lot Size Works
Lot size determines position granularity — how precisely you can size your trades. Small lot sizes allow fine-grained position sizing, which is critical for proper risk management. If the minimum lot is 1 BTC and you only want $500 of exposure, you can't properly size the trade. This is why contract specifications matter when choosing exchanges.
Why It Matters for Traders
Understanding lot size is fundamental to calculating position sizes. Your risk per trade (in dollars) divided by the distance to your stop-loss (in price) gives you the number of lots. If the math doesn't work out to whole lots, round down — never round up. Proper position sizing at the lot level is the foundation of professional risk management.