What counts as unusual options activity?
Open interest is the number of contracts still open at the end of the last session. When a contract trades more than its open interest in a day (volume ÷ open interest above 1×), much of that volume is probably new positions rather than traders closing old ones. Large premium on those trades suggests real money behind them.
- Vol / OI is the day’s volume divided by open interest. “new” means the contract had no open interest at all.
- Premium traded is volume × option price × contract size, in US dollars, so you can tell a few small lottery tickets from a big block.
- Delta shows how far in or out of the money the contract is: a far out-of-the-money call with a delta under 0.2 is a cheap, leveraged bet on a big move.
The default view needs at least $10,000 of premium for crypto and $25,000 for US options, to skip tiny trades.
Delayed/indicative data, not financial advice. Options are risky and can lose their whole value.
Frequently asked questions
Does unusual activity mean someone knows something?
Not necessarily. A big trade can be a hedge, part of a spread, a roll from another expiry or a market maker’s position. Volume alone doesn’t say whether the contract was bought or sold. Use it as a list of things to look into, not as a signal.
Which markets can it scan?
Two, picked with the Market buttons above the table. Crypto options (the default) come from Deribit’s public data, the biggest crypto options exchange: BTC and ETH, plus USDC-settled options on SOL, XRP, AVAX, TRX and HYPE. They need no key, and if Deribit can’t be reached the screener falls back to OKX’s BTC and ETH options. US options cover a watchlist of about 65 of the most active US stocks and ETFs (SPY, QQQ, IWM, NVDA, TSLA, AAPL and more) with your own free Alpaca key.
Is the data real-time?
No. Treat it as delayed and indicative, and not as financial advice. Deribit’s numbers are close to live (volume covers the last 24 hours). Alpaca’s free plan uses an indicative options feed: quotes may be delayed or modified, and trades are delayed. US open interest is published once a day, from the previous session. Turn on auto-refresh next to the results to update the table in place every 30 seconds, minute or 5 minutes.
Why do US options need a key?
US options prices (OPRA data) are licensed, so a website can’t hand them out for free. Alpaca gives anyone a free market-data key that includes an indicative options feed. Your key is saved only in your browser and sent only to Alpaca, never to us. Option open interest comes from Alpaca’s trading API, which free paper-trading keys can use too. See how to get a free Alpaca key.
How are crypto option prices and sizes shown?
Deribit quotes BTC and ETH options in coins; the screener converts every price to US dollars per coin using the expiry’s forward price. Volume and open interest are in coins (one Deribit BTC option is 1 BTC), so ratios such as volume ÷ open interest and put/call are directly comparable. Delta is worked out in your browser with the Black-Scholes formula from Deribit’s mark implied volatility.