This is a huge red flag. If the other co-founders won't show you this stuff, then you're not a co-founder in their eyes. Without the information you need, all

This is a huge red flag. If the other co-founders won't show you this stuff, then you're not a co-founder in their eyes. Without the information you need, all you can guess at is that someone is spending money without wanting to tell you - and this could be construed as stealing, since some of this money is yours (as an owner of the business). There may also be tax consequences that you may be on the hook for too! If you can't get the information from your co-founders, it will be necessary to get legal advice from a professional (not HN!)