State Street® SPDR® S&P® 400 U.S. Mid Cap UCITS ETF (Acc)

Rolling the dividends straight back in means your money compounds automatically, with nothing for you to reinvest by hand. The flip side is there is no cash income; the growth simply shows up as a higher fund value. Note that reinvested dividends can still be taxable in some countries even though you never receive the cash — the rules depend on where you live.

Owning every holding keeps things transparent — what is in the index is what the fund actually owns. It can be a touch costlier to run for indexes with thousands of tiny positions, since the fund has to buy and maintain them all. There is no swap bank involved, so there is no extra “what if the partner fails” question to weigh.

For example, a 0.20% fee works out at €0.20 a year for every €100 invested — that’s a generic illustration of the mechanic, not this fund’s own fee. It is skimmed quietly from inside the fund a little each day, so you never get a bill — but it drags on your return every year you hold. On a broad index ETF it is usually a small fraction of a percent; the gap between a cheap and a pricey fund looks tiny on day one but compounds over decades, which is why it is worth a glance.