The Ark Invest portfolio is known for taking aggressive bets. Portfolio manager Cathie Wood's Ark Innovation ETF (ARKK 1.29%) loaded up on a pair of biotech stocks throughout August and early September, and it wasn't the first time they caught her attention. Her style is to invest in growth businesses that are pursuing disruptive innovation within their industries. So while both are bound to be risky plays, there's reason to believe that these two companies have a decent shot at success. Here's what she bou ...