ETF Technical Indicators API: RSI, SMA, EMA, and MACD

Technical indicators are calculations over a price series, not independent market observations. Two providers can return different values when they use different adjustment rules, warm-up windows, price fields, or rounding.

SMA gives equal weight to observations in its window. EMA weights recent observations more heavily. RSI summarizes the balance of recent gains and losses, while MACD compares fast and slow EMAs and often includes a signal line.

Return the source date, period parameters, and enough warm-up history to explain the result. Treat indicators as research inputs rather than predictions, and keep the raw history endpoint available for users who need custom definitions.