Be more cautious about investing your 401k into Barry Silbert’s Bitcoin Investment Trust $GBTC. The (European) XBT Provider ETN is an open-ended fund which means it maintains a premium to the NAV close to 0% at all times. The Bitcoin Investment Trust is an inferior investment vehicle because it is a closed-end fund (it does not increase its holdings of the underlying asset when demand for the product increases) which means it is subject to wild swings in its premium, which has been as high as 150%. So you could make the mistake of buying when the premium is high and suffer swingeing losses even when the Bitcoin price is stable.
Always pay attention to Bitcoin. Most altcoins (every cryptocurrency except Bitcoin) are pegged more closely to Bitcoin than Asian currencies were to the USD during the Asian Financial Crisis. If Bitcoin price pump drastically, altcoins price can go down as people try to exit altcoins to ride the BTC profits; inversely, if Bitcoin prices dump drastically, altcoin prices can go down, too, as people exit altcoins to exchange back into fiat. The best times for altcoin growth appear when Bitcoin shows organic growth or decline, or remains stagnant in price.