(5,224.62-5,149.42)/5,149.42=1.01460 =+1.460%
(150.79-149.28)/149.28=1.01012 =+1.012 %
1.01460x1.01012=1.02487 =+2.487%
27,588 x 2.487% = 686

当たり前だけど>>628が正解っぽいね
指数と為替両方の値動きが大きい場合上昇率を足し算すると誤差が出る