Bitcoin closed 1.29% higher on Oct. 21, and 62 of the 88 largest non-stablecoin crypto assets rose with it, according to CoinMarketCap daily closes. Four days earlier, 80 of the same 88 coins fell, so the past two sessions mark a turn from a week in which most of the market sat out.
Breadth, the share of coins taking part in a move rather than the move in the biggest one, is how traders tell a market-wide rally from one carried by a few names. Le Coin measured it two ways across today's top 100 coins by market value, minus 12 stablecoins pegged to the dollar.
Two counts tell the story
The first count is simple: how many coins closed above or below the prior day's close. The second is how many closed above their 50-day moving average, the mean of the last 50 daily closes, which shows whether a coin sits above its own recent trend.
The week turned on Oct. 18
Fig. 1. Oct. 17 was the weakest day of the week, with 8 coins up and 80 down while bitcoin slipped 0.15%. By then only 38.6% of the 88 closed above their 50-day average. Oct. 20 was the broadest day, with 73 up and 15 down as bitcoin rose 1.33%. On Oct. 21, 52.3% sat above their 50-day average and 80.7% above their 200-day average, the same 52.3% reading as on Oct. 15.
Oct. 18 was the mixed case. Bitcoin rose 0.78%, 45 coins rose and 43 fell, and only 39.8% closed above their 50-day average.
In Le Coin's view, the two-day run from Oct. 20 is the first stretch this week in which the gains reached most of the market.
Narrow rallies are common
One up day says little on its own. Since Oct. 15, 2021, the first date with enough coins carrying a full 50-day record, bitcoin has closed higher on 881 days. On 455 of them, fewer than 40% of the coins in the sample closed above their 50-day average. A stricter test, more coins falling than rising on a bitcoin up day, applies to 158 of the 881.
Fig. 2. The mix swings by year. In 2022, 115 of 146 bitcoin up days were narrow by the 50-day test; in 2024 it was 71 of 191. This year, through Oct. 21, the count is 67 of 143.
The objection: today's winners write the history
These counts carry a survivorship bias. The sample is today's top 100, so coins that dropped out of the top 100 or died over the past five years are missing from the history. That pushes past breadth readings up and leaves the early years thin. In Le Coin's view, the historical counts describe how today's survivors behaved, not how the whole market did at the time.
A second limit is scale. Breadth weighs a small coin the same as a large one, so it says nothing about how much money moved, only how many names moved.
The tell
In Le Coin's view, the tell is the 50-day count. Oct. 21 cleared 40% with room to spare; a slide back below that mark on a bitcoin up day would put the market back in the narrow group that made up 455 of 881 such days since 2021. The next reading is the Oct. 22 UTC close.
Sources
- Prices and market data: CoinMarketCap, https://coinmarketcap.com (accessed Oct. 22, 2026, 12:24 a.m. ET). Daily closes (UTC days, closing 23:59:59.999 UTC) for the top 100 coins by market cap as of Oct. 22, 2026, 12:24 a.m. ET, excluding 12 stablecoins (88 coins), Oct. 15, 2021 to Oct. 21, 2026. Calculation by Le Coin: rose or fell is close versus prior close; above average means close above the simple 50-day or 200-day moving average, counted only for coins with a full window; a narrow up day is a bitcoin up day with fewer than 40% of eligible coins above their 50-day average, counted only on days with at least 50 eligible coins (881 bitcoin up days qualify).
Holding the Corner.
Not financial advice.