When investing in ETFs, the key is knowing what the fund actually holds. Two sites together complete your ETF research.
1. etf.com — per-ETF detail
It shows full holdings (not just the top 10) and sector mix as pie charts, accessible via etf.com/[ticker]. Check expense ratio, size and liquidity too.
2. ETF Database (etfdb) — search and compare
Strong for searching and comparing ETFs by sector/theme — perfect for "which semiconductor ETFs exist?" or "compare dividend ETFs."
3. Combined routine
Find theme candidates on etfdb → check each ETF's holdings and fees on etf.com → cross-check ratings on Morningstar. That covers most of what you need to pick an ETF.