[学习疑问] CFA L1 NOTES上面的一道time-weighted return相关的题 additional, 的, return, period

欧阳。

L. Adams buys  1,000 shares of Morris Tool stock for $35 per share. One year
later the stock is $38 per share and has paid a dividend of $1 .50 per share.
Adams reinvests the dividends in additional shares at the time. At the end of the
second year, the shares are trading for $37 and have paid  $2 dividends over the
period.
L. Burns buys 500 shares of Morris Tool stock for $35 per share. One year later
the stock is  $38 per share and has paid a dividend of $1.50 per share. Burns
reinvests the dividends in additional shares at that time and also buys 500
additional shares. At the end of the second year, the shares are trading for $37
and have paid $2 in dividends over the period.
A.  Compare the annual time-weighted return s for the accounts of the two
investors  (no calculation required).

想问一下为什么time-weighted return是相同的？

两人不是都把year1的dividend继续投资了，那样的话Adams的year2的beginning value应该比Burns的多500*1.5吧？但是ending value是相同的？

请给位指点