When you say bitcoin trading were you referring to trading bitcoin against fait e.g BTC/USDT or bitcoin against altcoin e.g BTC/ETH. If your goal is to increase the number of bitcoin you have by trading it against altcoin then you first have to change your exchange. Poloniex can't offer you better opportunities in doubling your bitcoin by trading altcoins. The exchange is outdated and most new projects don't consider listing their token on the exchange anymore as they don't have the volume/media hype to affect the price of any coin. You need an exchange that's active in listing new tokens/coins and it's left for you to research on which token/coins is worth trading also try trading coins with low supply as I consider coins with huge supplies to be a long term investment projects considering the project is worth investing in.