However, it also increases interest income generation strategies like the Amplify Energy & Natural Resources Covered Call ETF (NDIV). The fund invests in energy and natural resource companies while using a covered call strategy to generate income. NDIV generates income through energy stocks, dividends, and covered call premiums, not solely through rising oil prices. See More: Amplify’s Nathan Miller Talks Energy & Income ETFsHow Volatility Boosts Covered Call Option PremiumsOil price volatility doesn’t just affect crude. Traditional Energy FundsTraditional energy ETFs such as the Energy Select Sector SPDR Fund (XLE) primarily rely on appreciation in energy stocks to generate returns.