The easiest way to use Grizzly Bulls is to hold VOO in any brokerage account, sell it when the model generates a sell signal, and then rebuy it when the model generates the next buy signal. A slightly more advanced but more tax efficient approach would be to open a margin account with futures trading permissions and sell S&P 500 Futures (ES or MES) of equal value to your VOO during sell signals, then repurchase the contracts you sold during the next buy signal. With this method, I've found you can usually reduce your overall tax burden to less than 15% and you'll only owe taxes on the net result of your futures trading.