30d (30 days) is a label on cryptocurrency price and market-data sites for figures measured over the most recent rolling 30 days, most often the percentage price change and sometimes the total or average trading volume. The window ends at the current moment and starts exactly 30 days earlier, in UTC, so it is not the same as a calendar month. A 30-day view filters out much of the short-term noise visible in the 7d column and gives a rough sense of the medium-term trend. It can still mislead after a crash or a rally, because the result depends heavily on the starting point. Longer comparisons use measures such as year to date. Also see 24h (24 Hours).