We document and explain the sharp performance deterioration of smart beta indexes after the corresponding smart beta ETFs are launched for investment. While smart beta is purported to deliver excess returns through factor exposures, the market-adjusted return of smart beta indexes drops from about 3% “on paper” before ETF listings to about -0.50% to -1% after ETF listings. This performance decline cannot be explained by variation in factor premia, strategic timing, or diminishing returns to scale. Instead, we find strong evidence of data mining in the construction of smart beta indexes, which helps ETFs attract flows, as investors respond positively to backtests
etf list之前嘅data不可信
Rainbooow2025-06-19 18:19:33
但佢個網to Mar 2025 但張圖to 17 Jun 2025
撞正油價大升 佢又short9油
唔知佢遲啲會唔會改返