Most popular ETFs

1. Popularity by Assets Under Management (AUM): This measures the total value of all shares outstanding in an ETF.

SPDR S&P 500 ETF Trust (SPY): $488.3 billion

iShares Core S&P 500 ETF (IVV): $381.6 billion

Vanguard Total Stock Market ETF (VTI): $342.4 billion

Vanguard S&P 500 ETF (VOO): $365.6 billion

Invesco QQQ Trust Series I (QQQ): $226.6 billion

Vanguard FTSE Developed Markets ETF (VEA): $119.4 billion

Vanguard Value ETF (VTV): $104.5 billion

iShares Core MSCI EAFE ETF (IEFA): $103.9 billion

Vanguard Total Bond Market ETF (BND): $103.9 billion

iShares Core U.S. Aggregate Bond ETF (AGG): $100.9 billion

2. Popularity by Trading Volume: This measures the average number of shares traded daily in an ETF.

ProShares UltraPro Short QQQ (SQQQ): 130.5 million shares

ProShares UltraPro QQQ (TQQQ): 106.0 million shares

SPDR S&P 500 ETF Trust (SPY): 83.7 million shares

Direxion Daily Semiconductor Bull 3x Shares (SOXL): 71.8 million shares

iShares 20+ Year Treasury Bond ETF (TLT): 51.3 million shares

Invesco QQQ Trust Series I (QQQ): 50.9 million shares

iShares iBoxx $ High Yield Corporate Bond ETF (HYG): 47.6 million shares

Financial Select Sector SPDR Fund (XLF): 43.9 million shares

iShares Russell 2000 ETF (IWM): 40.4 million shares

iShares China Large-Cap ETF (FXI): 35.3 million shares

These lists are just a snapshot and can change depending on market conditions. It's important to do your own research before investing in any ETF.