Before You Call It a Fill, Read the Crypto Order Book
A chart can show a price touch while a limit order stays open. The gap is not necessarily a glitch: it is the difference between a market signal, available orders, price conditions and time instructions.
A price on a chart can appear to kiss your number and then carry on without you. I read that moment less as a betrayal by the screen and more as a reminder that 'the price' is a shorthand for several moving facts. We checked exchange rules rather than treating a limit order as a wish written on the market. The small delight is that order books are not being coy. They are being wonderfully literal.
A limit order says that a buyer will not pay above a stated price, or a seller will not accept below one. It does not say that someone must trade with that order the instant a chart prints a nearby number. A fill depends on the available orders, the platform's matching rules, the size requested and the order's own conditions. That makes a price touch useful evidence, not a universal receipt.
Three order types make three different promises
| Order type | What it prioritizes | What it cannot promise |
|---|---|---|
| Market order | Trying to execute immediately at the best available prices. | One exact price or a complete fill at that price. |
| Limit order | A stated price or better. | That enough compatible orders will appear to fill it. |
| Stop-limit order | A trigger first, then a limit price or better. | That the resulting limit order will fill after the trigger. |
Coinbase's help documentation describes a market order as one that executes at the best available current market price. Its market rules add the uncomfortable but essential detail: a market order can fill at multiple prices, and the result may be less favorable than the most recently observed trade price when the available orders are thin. That difference has a name, slippage. It is a mechanism, not a moral failing by the user.
A limit order flips the priority. Coinbase says a limit order can remain on the order book until it is canceled, expires or is completely filled. If it meets an opposite-side order immediately, it may execute right away. If it does not, it waits. I like this humble waiting-room image because it explains a lot of mystery: the order may be open, valid and unfilled all at once.
Why a chart touch can miss an open order
A chart is a summary of transactions or quotes, not a personal guarantee. The displayed last trade may be small, may occur on a different venue, or may not represent enough available interest to fill the whole order at your specified price. A platform also has its own matching and price-protection rules. Coinbase's published rules say market orders can be executed across several prices and that limit orders can either take existing orders immediately or remain on the book. Those mechanics make partial fills ordinary rather than suspicious.
Time instructions matter too. Coinbase lists good-til-canceled, immediate-or-cancel and fill-or-kill settings for limit orders. FINRA's plain-language guide on order qualifiers makes the general point: an immediate-or-cancel instruction takes what can be filled right away and cancels the rest, while fill-or-kill requires the whole amount immediately or nothing. Names and options vary by venue, which is exactly why the confirmation screen deserves a slower read than its tidy buttons invite.
A stop-limit has two moments, not one
Stop-limit orders add a second layer of precision and a second way to be disappointed. Kraken explains that the stop is a trigger. Once reached, it places a limit order, which then needs a willing opposite-side order at the limit price or better. If a fast market moves past that price, the order can remain unfilled. The trigger happened. The requested trade still did not.
That distinction becomes especially important in volatile markets. The CFTC warns that virtual-currency cash markets can experience sharp price swings and that market conditions can affect execution. It is not a reason to improvise a strategy from an explainer. It is a reason to know which promise an order type actually makes before assuming a familiar word such as 'stop' guarantees a particular outcome.
Read the order ticket as a small contract
Before treating a non-fill as a platform error, inspect four items: the side of the trade, the price condition, the size, and the time instruction. Then check the venue's definition of its displayed price and its order rules. We are not making a recommendation about whether anyone should trade. We are making a gentler claim: the most useful thing a trading screen can offer is a precise promise, and the most useful habit is reading that promise word for word.
Once that clicks, the chart becomes less maddening. A visible price is a weather report from the market. A fill is a documented match under particular terms. I think the difference is one of those unglamorous bits of literacy that earns its keep every time a confident-looking button invites a quick decision.
Sources
Every factual claim above traces to one of these. Links open in a new tab.
