Two columns on the options chain quietly tell you whether an option is worth trading at all: volume and open interest. They are measures of liquidity, how easily you can get in and out at a fair price, and ignoring them is a classic beginner trap.
Think of a busy farmers market versus a deserted stall. In the crowded market you buy and sell instantly at a fair price. At the empty stall, you take whatever bad price is on offer, because there is nobody else around.
What each number means
Volume is how many contracts traded today, a snapshot of fresh activity. Open interest is how many contracts are currently open and outstanding, a measure of standing interest built up over time. High numbers in both mean a crowded market for that option. Low numbers mean a ghost town.
Why liquidity is real money
The cost of low liquidity shows up in the bid-ask spread, the gap between what buyers offer and sellers want. In a liquid option that gap is a penny or two. In an illiquid one it can be wide, and you lose that difference every time you enter and exit. Trade enough illiquid options and the spreads quietly eat your returns, even when your trades are “right.”
A simple habit
Before selling any option, glance at its volume and open interest. Favor options with healthy numbers in both, especially on liquid stocks and ETFs, so you can enter and exit near a fair price. If an option barely trades, skip it, no premium is worth being trapped in a position you cannot close cleanly.
Liquidity is freedom. A liquid option lets you change your mind, roll, or close in a hurry at a fair price. An illiquid one can trap you, so treat healthy volume and open interest as a requirement, not a bonus.
- Volume is today’s activity; open interest is the total contracts currently open. Both measure liquidity.
- Low liquidity means a wide bid-ask spread, which quietly costs you on every entry and exit.
- Favor options with healthy volume and open interest so you can always trade at a fair price.
This article is educational and is not investment advice. Options involve risk, including the possible loss of principal. Examples and premiums shown are illustrative and change with the market. Practice with paper trading before committing real money.