Tick size
Definition · Level 0 · Market basics
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The minimum price increment a security can be quoted in: one cent for US stocks at $1 or more. A 2024 SEC rule adds a half-cent step for the most tightly quoted stocks, now due from November 2027.
Example
At a one-cent increment, the next bid above 20.10 is 20.11.
Rules and market figures change: check the current ones before relying on this.
Where Tradecraft teaches it
Level 0 · Market basics, in the lesson “Reading the quote”: Bid, offer, spread, size and depth, and what they tell you about the real cost of trading.
Related terms
- ADVAverage daily volume: the typical number of shares traded per day over a lookback window (often 20 or 30 days), the yardstick for how big an order…
- Bid / offerThe highest price a buyer is currently showing, and the lowest price a seller is asking (also called the ask).
- Bid-ask spreadAsk minus bid: the price of immediacy. Crossing it costs half of it versus mid each way, and a round trip costs all of it.
- Last pricePrice of the most recent trade (the print).
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