I'm a babe in woods newbie with all things crypto, but a seasoned stock trader.
I made a small buy of BTC on coinbase a few weeks ago and tried to buy LTC, on Thursday, got a message the instant buy happened then nothing. Still nothing after several days.

I realized I need to speed up my choice of a new exchange.
This post and the comments are particularly timely.
I'm leaning toward Poloniex with a strong interest in Kraken after
a recommendation from Trace Mayer.
I do want the ability to trade at light speed. I got jammed up as a day trader
many years ago with internet glitches. I lost several thousand dollars in less than fifteen minutes. YIKES!