You don't need a big stash of BTC to make a nice chunk of money day trading. I think everyone is thinking too much like a stock INVESTOR (buy many cheap shares, sell many at price-sell trigger) and not a VOLATILE commodities trader (make even 2% gains over and over then double your investment after only 36 trades).

Day trading loves the law of compounding interest. A simplified version is the "rule of 72." Take the gain percentage (say 4%) and put it in the denominator with 72 as the numerator. This is approximately the number of similar trades it will take to double the starting amount.

72/4 = 18
1.04 x 1.04 x 1.04 ... 18 times is 2.0258 etc.

Of course BTC prices won't swing in 4% pluses and minuses for you, so you look for smaller swings, even 1%. And, don't put your entire bankroll at risk. Use maybe a quarter of it. It will take 72 trades at 1% to double the amount you're trading with. 2 trades a day for a little more than a month.