as regulatory environment tightens in Europe I am being more careful by saving my data more regularly, reconciling my trades, making sure that everything is explainable in a future audit.

for example, on hyperliquid i can only go back about 10k trade records. for me that lasts about 3 months and im already not able to go back any further. if I had to prove transactions from earlier periods and I did not have a database with the entire history, I would not be able to prove the operations I am reporting.
I don't have to go back as I have every single trade recorded in a database, but this is the first time I am doing it and I created a secondary reconciler that goes directly to the exchange and matches with my database.
I have been able to avoid doing this in too much depth until last year because I reported any gains as a personal income, and in PT your taxable event is based on coin -> fiat conversion so it didn't matter that much, although tbh i should've kept more detailed records.
if I didn't do this it would be a mess in the future to solve. I've spent the last 3 days really thinking carefully around this and making sure that from now on I don't have any gaps in my data.
built a standard process for all exchanges regardless of their idiosyncrasies, which are a lot...
so far I am about 1.2k off the PnL of what my manual balance tracker says I should have. it's a minor % deviation which is fine.
that manual balance tracker is basically an export I do each of every balance across my entire holdings and serves as a source of truth because thats literally cash sitting on wallets/exchanges so we cant deviate much from it.
so far so good. keep your records guys, might not be super exciting task, but maybe one day you'll be asked where that money is coming from and you cant answer.