I was very frustrated when you think that BTC price is very fluctuate. Tether is a stable coin as like others 4-5 stablecoin but tether is the best one. After everything if you can't trust USDT coin than you can only USD which is available in several exchange, of course should use very trust exchange. Although 10K isn't very big amount to hold in USDT because I trust Tether.
Tether is indeed the best for stable coins and in various large markets also applies the Tether market, I often use Tether to buy and sell altcoin because the value is the same so if prices start to fall I will sell it with Tether and buy again at the lowest price