<nitpick>there's no leverage if you use $500K to buy $500K of AAPL. Financial leverage is created when you multiply the buying power of a fixed amount of money through financial vehicles like options. It could be as simple as using the fact that your brokerage is usually willing to loan you money up to a certain percent of your assets in the account. You can then use that loaned money to buy more stock, perhaps as a hedge or perhaps to double-down on your original investment thesis</nitpick>