Group 1 - ARK Innovation ETF (ARKK) was a top-performing exchange-traded fund in the second quarter, driven by Cathy Wood's focus on electric vehicles, crypto, and AI crypto stocks [1] - The aggressive concentration in innovative sectors has significantly benefited the ETF, pushing it to the top of its category [1] Group 2 - The article emphasizes the importance of keeping an eye on high-tech and early growth companies for potential investment opportunities [1]