Price changes: 1h, 24h, 1D, 1W, YTD and the rest

How every percentage on Market Check is measured, and why two sites can show different numbers for the same asset.

"Up 3%" sounds like a simple fact. It is really an answer to two hidden questions: up 3% compared with what price, and measured from when? Different sites answer them differently, which is the most common reason a figure here does not match your broker's app. This guide sets out the arithmetic and the conventions.

The arithmetic

A percentage change is the new price minus the old price, divided by the old price:

change % = (latest price − reference price) ÷ reference price × 100

If a stock closed yesterday at $200 and trades now at $206, it is up (206 − 200) ÷ 200 = 3%. If it falls back to $200 tomorrow, that is a fall of 6 ÷ 206, about 2.9%, not 3%, because the reference price is now higher.

That asymmetry matters more as moves get larger. A fall of 50% needs a rise of 100% to get back to where it started. A fall of 90% needs a rise of 900%. This is why a coin that is "up 80% this month" after a long slide can still be far below where it was a year ago.

Crypto windows are rolling

Crypto trades around the clock, every day of the year, so there is no "close". For coins, Market Check shows 1h, 24h, 7d, 30d and 1y as rolling windows that end now, as reported by CoinGecko. "24h" at 3 p.m. means "since 3 p.m. yesterday". It is not "today" in any calendar sense, and it changes every minute even if the price stands still, because the starting point keeps sliding forward.

Stock windows are anchored to closes

Stocks, funds, indexes and commodities trade in sessions, so their windows are anchored to official closing prices:

1D compares the latest price with the previous session's official close. Before the open and at weekends, it shows the last full session's change.
1W and 1M compare with the close 7 and 30 calendar days earlier, using the nearest trading day on or before that date.
YTD (year to date) compares with the last close of the previous year.
1Y compares with the close one year ago.

So "1D" for a stock and "24h" for a coin are not the same measurement, even if they are shown side by side. On a Monday morning, a stock's 1D still describes Friday's session, while a coin's 24h covers Sunday into Monday.

Why your broker may show something different

Delay. Free public data, including what Market Check uses, can run behind the exchange. Your broker's live quote is the one to trust.
Extended hours. Some apps include pre-market and after-hours trades in the day's change; others freeze at the 4:00 p.m. close until the next session.
Reference price. One app may use the previous official close, another the last trade of the previous day including after-hours.
Different venues. A coin trades on many exchanges at slightly different prices. CoinGecko publishes an aggregate; a single exchange shows its own.
Dividends. Market Check's changes are price changes only. A "total return" figure that adds back dividends will be higher for income-paying stocks and funds.

Differences of a few hundredths of a percent are normal. A large gap usually means one of the two prices is stale; check the "updated" time at the top of the page.

Putting a change in context

A percentage on its own does not tell you whether a move is large for that asset. A 2% day is unusual for a broad index fund and routine for a small cryptocurrency. Before treating a number as news, compare it with the same asset over longer windows, or open its chart. The markets tables show day, week, month and year side by side for exactly this reason.

Full details of every window, source and refresh interval are on the sources and methods page. Nothing here is financial advice.