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Universe. The database aims to cover every exchange-traded product listed on major U.S. exchanges. The vendor's ETF list is synced daily; funds that stop quoting on a U.S. exchange are marked inactive and kept (never deleted). Newly listed funds join automatically.

Quotes. Delayed vendor quotes (typically 15–20+ minutes), refreshed hourly for the whole universe. Every quote shows the vendor's own timestamp where available.

Returns. Computed by ETF Explorer from daily closing data. Price return uses unadjusted closes: close(end) ÷ close(start) − 1. Total return uses the dividend-adjusted close series (distributions treated as reinvested). Periods of three years and longer are annualized: (1+r)^(1/years) − 1. YTD measures from the last close of the prior year. A figure is omitted (—) when the fund's history doesn't cover at least ~90% of the period, or when a data gap of more than three weeks sits at the period boundary. "Since inception" measures from the start of our stored daily series; for a small number of funds this can begin later than the fund's true inception date (the inception date shown on the page is the issuer's).

Trailing yield & distribution growth. Yield (TTM) = cash distributions over the last 365 days ÷ current price. It is NOT the SEC 30-day yield (not supplied by our data source; the issuer's page has it). Distribution growth compares trailing-12-month sums: 1-year growth needs ≥ 2.2 years of history; 3-/5-year growth is the annualized change vs the TTM sum 3/5 years earlier and needs correspondingly longer history. Funds with insufficient history are excluded from those rankings rather than estimated.

Risk statistics. From daily total-return series: volatility = stdev of daily returns × √252; Sharpe = (annualized return − risk-free) ÷ annualized volatility, risk-free = 3-month T-bill (FRED DTB3, value shown on each fund page); Sortino uses downside deviation (√252-scaled root-mean-square of negative days); max drawdown = worst peak-to-trough of the adjusted series in the window; beta and correlation are computed against SPY as the S&P 500 proxy over 3 and 1 years respectively. At least ~40 return observations (and ~85% window coverage) are required, otherwise the statistic is omitted.

Fund-flow estimates. ETF Explorer snapshots each fund's reported AUM daily. Estimated net flow over a window = AUM(end) − AUM(start) × (1 + price return). This removes the market-move effect but remains an estimate — it is not issuer creation/redemption data, and it appears with that label everywhere.

Trending score. A transparent popularity score, recomputed daily: 2×min(volume ÷ average volume, 6) + 0.8×min(|day move %|, 10) + 0.5×min(news articles tagged to the fund in 7 days, 12) + 0.6×min(page views on this site in 7 days, 20) + 0.6×min(|estimated 1-week flow % of AUM|, 10). Funds under $50M are not scored. Trending measures attention on this site — never investment quality.

Classification. Categories, leverage/inverse flags, currency hedging, option-income and buffer tags, and geography come from deterministic rules over the fund's name, the issuer's own description, and the actual reported sector/country weightings (e.g. "single-country" requires the country to dominate reported weights AND appear in the fund name). Active vs. passive is taken from the issuer description where stated; otherwise it is shown as "not stated" — never guessed. The underlying index is parsed from the fund name only when unambiguous.

Premium/discount. (Delayed price − last reported NAV) ÷ NAV, labeled indicative because the two figures have different timestamps. The issuer's official premium/discount history governs.

Missing data. "—" or "N/A" means the source has not published a value or our coverage has not reached it yet. We never fill gaps with invented numbers, and AI is never used to generate market data (it only summarizes figures already in the database, with labels).

Refresh cadence. Quotes & news hourly · universe, profiles/AUM, EOD history, top-1500 holdings & distributions, and all derived analytics daily · full-universe holdings and distributions weekly · data briefs after fresh data lands. Each dataset renders its own as-of date.