What is a gap in a stock? Opening gaps, the four types, and what to do about them

A gap is a situation where a stock opens at a price far from the previous close, with no trading at all occurring between the two prices. On the chart it looks like a hole: today's candle starts above (gap up) or below (gap down) yesterday's candle, with no overlap. The gap is created because new information arrived while the market was closed, and the first price of the morning already reflects it.

Why this matters more for a swing trader than for an investor: swing trading lives on entries and stops at defined prices, and a gap is the most common way price skips over both. A stop at 47 doesn't help when the stock opens at 44. That's why you need to understand not just what the gap says about the stock, but what it does to the trade plan.

What Creates a Gap

The New York Stock Exchange is open six and a half hours a day, and the world keeps happening the rest of the time. A company releases a quarterly report after the close, an analyst changes a recommendation before the open, a macro figure comes out at 8:30 in the morning, or China announced something overnight. By the time the bell rings, buyers and sellers already know the news, and today's first price is set where they're willing to meet each other, not where yesterday left off.

Dual-listed Israeli stocks (traded both in Tel Aviv and in the US) have an additional source of gaps: the calendar. The trading days and holidays of the two exchanges don't overlap, and every time one of them traded while the other was closed, the next opening on the closed exchange "fills the gap" on what happened on the other side. Those who trade both sides see such structural gaps almost every week.

The Four Types, and Why the Difference Between Them Matters

Classic technical analysis literature classifies gaps by their place in the trend, not by their size. This classification is useful because it tells you what's likely to happen next, and that can be checked on the chart without guessing.

"Gaps Always Close": A Dangerous Half-Truth

"Gap fill" means the price returns and trades within the range it skipped over. The saying that gaps "always close" is true only in a useless sense: over enough years, almost every price appears again. The practical question is whenand on that, the saying is silent. A regular gap in a consolidation does indeed close within days, in most cases. A breakout gap on a surprising report can stay open for years, and whoever "sold the gap" expecting it to close is holding a short against a trend that just began.

We can't give a percentage here like "such-and-such percent of gaps close within a week," because a number like that depends entirely on the definition (what size counts as a gap, which market, which period), and we don't have our own measurement we can stand behind. What can be said: the larger the gap, the higher the volume, and the clearer the reason, the less likely it is to close soon.

What a gap does to your trade plan

Here's the difference between understanding gaps and getting hurt by them. A swing trader works with three prices: entry, stop, and target. A gap can skip over any one of them.

• Gap beyond the stop: A stop order becomes a market order the moment the price crosses it, and it fills at the opening price, not at the stop price. Stop at47 With an open at44 = a loss of 6 instead of 3This is the only reason for a position-size cap: it doesn't protect you from the stop, it protects you from what happens when the stop doesn't fill at its price. Position size determines how much such a gap hurts.
• Gap beyond the entry: You planned to buy on a breakout above 100 and the stock opened at106Chasing buys at a price the original stop no longer fits. In TechAnalyzer's track record the rule is strict: a position is opened only on a candle whose range actually contains the entry price. A setup that the price skipped over remains "unfilled" and doesn't enter the record, even if the stock kept rising. This costs us some good trades, and it prevents the record from counting entries that no one could have actually made.
• Gap into the target: The pleasant problem. A sell order at the target fills at the open, usually above the target. This time the gap works in your favor.
• The gap as a level: After a breakout gap, the upper edge of the gap (in a gap-up) tends to act as support: those who missed it wait there. A return into the gap and its full closure is a signal that the market has reversed. Many traders place their stop below the lower edge of the gap for this reason.

Trading the gap itself: what's common, and what it costs

Two common approaches, opposite to each other. "Gap and Go"Buying in the morning on a gap-up with volume, assuming it's a breakout or continuation gap, with a stop below the low of the first few minutes. "Gap Fade"Trading against the gap, assuming it's a regular or exhaustion gap that will close. Both are mainly intraday trading, and both live and die on correctly identifying the type, which, as mentioned, is known with certainty only in hindsight.

For a swing trader, the more cautious approach is not to trade the gap day at all, and to let the following days tell what type it was. A gap that holds for three-four days and builds a small base above the gap gives an entry with a reasonable stop (below the base) and a clear answer to the question "when do I know I'm wrong" (the gap closing). This gives up the first days of the move, and that's the price of not guessing. Breakout and Retest is the same idea without the gap.