Defined contribution (DC) plans have driven the demand for cost-effective, diversified, and easily tradeable investment products like exchange-traded funds (ETFs). Unlike defined benefit plans, where the employer guarantees payouts, DC plans place the responsibility for investment decisions and risks on individuals, who increasingly opt for ETFs for their low costs and broad market exposure.

A. The rise of financial technology companies: While fintech has contributed to the growth of investment products, it is not a primary driver of ETF usage.

C. The emergence of cryptocurrency: Cryptocurrencies are separate financial products and are not directly tied to the use of ETFs.

D. The popularity of robo-advisors: Robo-advisors use ETFs extensively, but this is a result of their popularity rather than a cause of ETF growth.