Amundi JPX-Nikkei 400 UCITS ETF - JPY (C)

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.

Rather than hold the shares, the fund signs a swap with a bank that agrees to pay it the index return. This can track some markets very tightly and cheaply, but it adds counterparty risk — the small chance the swap partner cannot pay — which regulated funds limit and back with collateral. It reaches the same index a different way, with a different set of trade-offs to physical funds.

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.