$XL2CSOPSMSN(07747.HK) Many people have a misconception that if the 2x ETF doesn't keep up with the underlying stock's gain today, it's due to decay. Actually, this is a return to net asset value (NAV). Leveraged decay only occurs over multiple days of volatility, not on a single day. Yesterday, Samsung had a 3.5% premium, and SK Hynix had a 7.5% premium. Today, Samsung rose 2.5%, so the 2x ETF should have risen 5%. However, affected by the overall Hong Kong market, it closed down 1%. Factoring in yesterday's 3.5% premium, it's at a 2.5% discount today. SK Hynix's underlying stock fell 0.2%, so the 2x ETF fell 6.8%. Factoring in yesterday's 7.5% premium, there's still about a 1% premium now, basically even.$XL2CSOPHYNIX(07709.HK)