Altcoin fatigue has taken over the crypto markets, and most trading activity has circled back to concentrate on Bitcoin (BTC). Typically, the original cryptocurrency takes up around 30% of all trades, but the proportion increased to more than 37% as of December 14. While prices struggle to remain in their current range, another sell-off has pushed them closer to $3,300.An even more dramatic change for BTC trading is the expanded influence of Tether (USDT) pairs. During Thursday’s sell-off, more than 71% of all trades happened in the BTC/USDT pair, based on data from CryptoCompare. Later, the proportion fell to about 68%, remaining relatively high.Altcoins still have a relatively high market dominance due to their sheer number. Some tokens and coins continue to see the occasional pump. However, Bitcoin’s dominance expanded to more than 54% after dropping to as low as 32% in January.