ETFs w/ most active options trading:

$SPDR S&P 500 ETF (SPY.US)$ - 9.510M
$Invesco QQQ Trust (QQQ.US)$ - 3.559M
$iShares Russell 2000 ETF (IWM.US)$ - 1.005M
$iShares 20+ Year Treasury Bond ETF (TLT.US)$ - 414k
$ProShares UltraPro QQQ ETF (TQQQ.US)$ - 349k
$Ishares Iboxx $ High Yield Corporate Bond Etf (HYG.US)$ - 277k
$iShares MSCI Emerging Markets ETF (EEM.US)$ - 272k
$ARK Innovation ETF (ARKK.US)$ - 256k
$iShares MSCI Brazil ETF (EWZ.US)$ - 245k
$ProShares Ultra VIX Short-Term Futures ETF (UVXY.US)$ - 240k
$Spdr Series Trust S&P Regional Bkg Etf (KRE.US)$ - 221k
$ProShares UltraPro Short QQQ ETF (SQQQ.US)$ - 214k
$SPDR Gold ETF (GLD.US)$ - 195k
$iShares Silver Trust (SLV.US)$ - 185k
$Financial Select Sector SPDR Fund (XLF.US)$ - 185k
$VanEck Gold Miners Equity ETF (GDX.US)$ - 176k
$Energy Select Sector SPDR Fund (XLE.US)$ - 111k
$Direxion Daily Semiconductor Bull 3x Shares ETF (SOXL.US)$ - 100k
$iShares China Large-Cap ETF (FXI.US)$ - 88k