Yes, couldnt find any Exchange with many altcoins and usd. Or any way of immediate Transfer of USD to BTC and BTC to USD.
1 Tether (USDT) is worth 1 dollar, so you can for example, sell 1 BTC for 4350 USDT and rebuy when the price goes down without needing to transfer money between your bank account and the exchange.
But I would be careful, they seem to be shady at the moment. Check the links:
https[Suspicious link removed]d/status/904867721652797440
https://www.reddit.com/r/btc/comments/6y4p49/tether_has_created_a_total_of_70_million_in_new/
Yeah i heard about Tether already, definitely not a good solution atm, thanks anyway