Low risk entry on TQQQTQQQ (and the QQQ's) have been range-bound for the past few days, approx. between $31-$35 ($4). This is a little more than the 14-day ATR of $3.00.
In light of this, one way to paper trade this would be to take a long above $35 with stops at $31 and shorts below $31 with stops at $35. This is an 11.5% risk on a 3x leveraged stock which is a relatively tight range for the product's known volatility.