Crypto options glossary
What is delta in options?
Delta is how much an option's price moves when the underlying moves by one dollar. A Bitcoin call with a delta of 0.50 gains about 50 cents per BTC when Bitcoin rises one dollar. Calls have deltas from 0 to 1, puts from 0 to −1, and at-the-money options sit near 0.5.
- Calls run from 0 to 1. Puts run from 0 to −1.
- At the money is about 0.5; deep in the money nears 1; far out of the money nears 0.
- Traders read delta as a rough chance of ending in the money.
- Position delta = delta × lots × 0.001 BTC: your exposure in Bitcoin.
| Strike | Call delta | Put delta |
|---|---|---|
| 82,500 | 0.63 | −0.36 |
| 83,000 | 0.59 | −0.40 |
| 83,500 | 0.55 | −0.45 |
| 84,000 | 0.50 | −0.50 |
| 84,500 | 0.46 | −0.55 |
| 85,000 | 0.41 | −0.59 |
| 85,500 | 0.37 | −0.64 |
The 84,000 call has a delta of 0.50. If Bitcoin rises 1,000, it gains about 504 per BTC: 5.04 USDT on 10 lots (0.01 BTC).
Bitcoin at 83,927. Deltas as Delta Exchange publishes them; the highlighted row is at the money.
Questions people ask
What does a delta of 0.30 mean?
The option moves about 0.30 dollars per BTC for each dollar Bitcoin moves, and many traders read it as roughly a 30% chance of ending in the money. It is a quick guide, not an exact probability.
Why is put delta negative?
Because a put gains when Bitcoin falls. A put with a delta of −0.40 gains about 0.40 per BTC for every dollar Bitcoin drops.
What is delta neutral?
A position whose deltas add up to about zero, so small Bitcoin moves barely change its value. A short strangle starts close to delta neutral; as Bitcoin moves, its delta grows, which is what gamma measures.
What is the delta of an at-the-money option?
About 0.50 for a call and about −0.50 for a put. It means the option moves about half as much as Bitcoin, and the market sees roughly an even chance of it finishing in the money.
Does delta change as expiry gets closer?
Yes. With less time left, out-of-the-money options drift toward a delta of 0 and in-the-money options toward 1, because the outcome is becoming more certain. At-the-money options stay near 0.5 but become very sensitive to small moves.
How do you delta hedge an options position?
Add up the position's delta in Bitcoin, then take the opposite amount in a perpetual or future. A position that is long 0.004 BTC of delta is hedged by selling 0.004 BTC of the perpetual. The hedge needs adjusting as delta changes.
Delta, worked in numbers
An example with round numbers. Bitcoin is at 80,000, and the 81,000 call is quoted at 900 per Bitcoin with a delta of 0.40.
Bitcoin rises 500. The call gains about 0.40 × 500 = 200 and is now worth about 1,100. On 10 lots, which is 0.01 BTC, that is 2 USDT. If Bitcoin falls 500 instead, the call loses about 200 and is worth 700. It is 'about' each time because delta itself moves as the price moves, which is what gamma measures.
Delta also tells you the size of your position in Bitcoin terms. Ten lots of a 0.40-delta call behave, for small moves, like holding 10 × 0.001 × 0.40 = 0.004 BTC. A sold call has the opposite sign: sell those ten lots and you are short 0.004 BTC.
Typical deltas, from deep in the money to far out
Delta follows moneyness. These are typical values, not exact ones; the card above shows today's.
| Option | Call delta | Put delta |
|---|---|---|
| Deep in the money | about 0.90 | about −0.90 |
| At the money | about 0.50 | about −0.50 |
| Out of the money | about 0.20 | about −0.20 |
| Far out of the money | about 0.05 | about −0.05 |
A call and a put at the same strike and expiry have deltas that are about 1 apart: a 0.40 call sits beside a −0.60 put.
How traders use delta
Four everyday uses.
- Choosing strikes. Option sellers often sell strikes with a delta around 0.15 to 0.20, far enough out that the market gives them a small chance of finishing in the money.
- A quick probability. A 0.20-delta option is read as roughly a one-in-five chance of ending in the money. It is a rule of thumb, not an exact figure.
- Measuring exposure. Adding up the deltas of every leg shows whether a position really is neutral, or is quietly long or short Bitcoin.
- Hedging. A position's delta can be cancelled with a perpetual future, which has a delta of exactly one per Bitcoin.
How delta changes as Bitcoin moves
Delta is not fixed. As Bitcoin rises, call deltas grow toward 1 and put deltas shrink toward 0; as it falls, the reverse. How fast delta changes is gamma, and close to expiry it can change very quickly.
Choosing strikes by delta
Many option sellers pick strikes by delta instead of by distance: a 0.15-delta call sits as far out as today's volatility requires. Because Bitcoin's volatility changes from week to week, choosing by delta keeps the risk more even than a fixed distance. Algoclear's strategy rules can pick strikes by delta, distance, premium or an exact strike.
Delta, the Greek, and Delta, the exchange
The name clash is a coincidence. Delta Exchange India is the exchange; delta the Greek is a property of every option on any exchange. Delta Exchange publishes the delta of every Bitcoin, Ethereum and Gold option, and Algoclear shows it beside each strike on the option chain.
Common mistakes with delta
Delta is simple, which makes it easy to over-trust.
- Treating it as fixed. After a big move the delta you entered with is no longer the delta you have.
- Reading it as an exact probability. It is close, and closer for short expiries, but it is a guide.
- Forgetting the sign on sold options. A sold put is long delta; a sold call is short delta.
- Ignoring expiry day. In the last hours, deltas of near-the-money options jump toward 0 or 1 on small moves.
Written by the Algoclear team · Updated 22 September 2026 · Examples use Bitcoin options on Delta Exchange India.
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