Correlation (weekly returns), annualized covariance, beta vs S&P 500, volatility, max drawdown, calendar-year returns, fund facts (fees, yield, AUM) or stock fundamentals (market cap, P/E), and ETF holdings overlap with top common positions, for a pair of US stocks or ETFs. Popular pairs come from PairBook's precomputed matrix; any other pair of covered symbols is computed on demand from the weekly return series. Example: a=QQQ, b=VOO. Symbol order does not matter. Covers ~4,700 US-listed stocks and ETFs only (no crypto, no foreign listings, no inverse/leveraged short funds, no intraday data); figures use weekly closes and refresh once per trading day. Unknown tickers return an error: resolve them with resolve_symbol first.

One US stock or ETF: beta vs S&P 500, annualized volatility, 1/3/5-year returns, max drawdown, calendar-year returns, fund facts or stock fundamentals, and its most correlated assets. For diversification candidates use find_diversifiers. Covers ~4,700 US-listed stocks and ETFs only (no crypto, no foreign listings, no inverse/leveraged short funds, no intraday data); figures use weekly closes and refresh once per trading day. Unknown tickers return an error: resolve them with resolve_symbol first.

Assets with the lowest or most negative 3-year correlation to the given US stock or ETF, each with its name and kind so you can screen them. Raw lowest-correlation list: it can contain leveraged/inverse ETNs, volatility products and illiquid micro-caps. Check name and kind before presenting anything as a portfolio diversifier. Covers ~4,700 US-listed stocks and ETFs only (no crypto, no foreign listings, no inverse/leveraged short funds, no intraday data); figures use weekly closes and refresh once per trading day. Unknown tickers return an error: resolve them with resolve_symbol first.

Weekly return series for one US stock or ETF (W-FRI, most recent last, all series end on the same Friday so tails align across symbols), for custom correlation or risk math. Covers ~4,700 US-listed stocks and ETFs only (no crypto, no foreign listings, no inverse/leveraged short funds, no intraday data); figures use weekly closes and refresh once per trading day. Unknown tickers return an error: resolve them with resolve_symbol first.

Find the ticker for a company or fund name (e.g. 'nvidia' -> NVDA) across PairBook's ~4,700 covered US stocks and ETFs. Call this before other tools whenever the exact ticker is uncertain or a lookup returned not-found.

Whole-portfolio risk and diversification analysis for 2 to 30 US stocks or ETFs: which positions are redundant, where the risk concentrates (Euler risk contributions), what actually diversifies, portfolio volatility, beta and market R2, diversification ratio, effective number of independent bets, correlation blocks that move together, max drawdown of the mix vs SPY, and issuer-sourced holdings-overlap warnings between the ETFs held. Use compare_pair for just two assets. Covers ~4,700 US-listed stocks and ETFs only (no crypto, no foreign listings, no inverse/leveraged short funds, no intraday data); figures use weekly closes and refresh once per trading day. Unknown tickers return an error: resolve them with resolve_symbol first.