How would I trade against LTC or BTC? As in if I thought the price was going to drop? Can you do that with Cryptos?
I dont know of any platform that allows this directly, what you can do however is borrow BTC/LTC send to an exchange, sell, wait for drop, rebuy, pay back loan.
You will need collateral or other securities though. This board has a lending section (Warning: Newbies asking for a loan w/o collateral and escrow will most likely get bad rep) and BTCJam might be something that can work for you.