Is there a problem with investing in a digital currency and letting it sit on Shabbat and holidays? It's fairly volatile and can increase or decrease greatly in value. So I'm wondering if these potential gains and losses occurring during holy days can pose a halachic problem, even if you're not buying or selling on those days.
Is there a difference between this and buying a particular paper currency, hoping it will appreciate in value faster than another?
Some well known cryptocurrencies include Bitcoin and Ethereum.