這裡列出元大台灣50正2（00631L）最近兩年的逐月報酬，對照加權指數，並算出每個月的實際倍數。
累積報酬的倍數不會剛好是 2。槓桿 ETF 每日再平衡，趨勢順的時候大於 2、來回震盪的時候小於 2——這叫路徑依賴。連續兩個月 +10%／−10%，大盤累積 −1%，兩倍卻是 −4%。
⚠️ 正2 追蹤的是臺灣50指數的單日正向兩倍，不是加權指數兩倍，成分也不同。所以「實際倍數」那一欄本來就不會乾淨；大盤月報酬接近 0 時分母太小，數字沒有意義，以「—」略過。
Monthly returns for Yuanta Taiwan 50 Bull 2X (00631L) over the past two years, against the TAIEX, with the realised multiple for each month.
Cumulative returns are never exactly 2x. Leveraged ETFs rebalance daily: the multiple exceeds 2 in a smooth trend and falls below 2 in choppy markets. Two months of +10% then −10% leaves the index at −1% but the 2x fund at −4%.
⚠️ The fund tracks twice the daily move of the Taiwan 50 Index, not the TAIEX, and holds different constituents. Months where the index moved less than 0.2% show "—" because the ratio is meaningless.