The top crypto coin to buy question sounds different once altcoins start moving as a group, and on September 21 they did: Glassnode’s Altcoin Cycle Signal flipped to altcoin season at 81.25 out of 100, per CoinEdition. XRP funds pulled $20.02 million on September 22, per Coinglass data, and ETH touched $2,800, per Benzinga.