VOO Historical Data API: Prices, Returns, and Backtests

VOO is Vanguard’s S&P 500 ETF. It follows a similar benchmark to SPY but has a different inception date, fee structure, trading profile, and distribution history. Those differences matter when comparing long-term results.

When comparing VOO and SPY, begin on the first date available for both assets. Otherwise, a longer history for one fund can distort the conclusion. Use adjusted prices consistently and disclose whether distributions are reinvested.

Fetch VOO history on the server, cache stable historical windows, and request only the latest portion during routine refreshes. From there, calculate total return, CAGR, drawdown, and rolling volatility or call a dedicated backtesting endpoint.