The Altcoin Season Index has fallen to 45 on August 20, according to Coinmarketcap. Earlier, on August 11, it was at 29.
This index shows how many of the top 100 cryptocurrencies are doing better than Bitcoin in the last 90 days. Right now, about 45 out of 100 coins have performed better than Bitcoin.
The index is used to check if the crypto market is in an “altcoin season” (a time when altcoins grow faster than Bitcoin).