After months of obtaining contradictory advice and suggestions by various 'professionals' I believe I finally have the answer to this dilemma...since daytrading brokers only offer SEP IRAs and Roth IRAs, how do you go about setting up a Roth solo K account for trading? Apparently the answer is that you set up a solo K account as a trust. You are the trustee, as opposed to when you open a retirement account with Fidelity for example, Fidelity would be the trustee. The initial suggestion I had been given was to open a Roth solo K with Fidelity or some other outfit, then convert that account to a Roth IRA, then rollover that Roth IRA into your daytrading broker. I think this is doable, but I couldn't even get the IRS to tell me whether converting from a solo K to IRA is legal. (There has to be a 'triggering event' such as turning 59 1/2, loss of employment, etc. to get funds out of a qualified plan). The issue is, can you arbitrarily close a qualified plan whenever you want to? Is that in itself considered a 'triggering event'? I got plenty of people telling me yes, and just as many telling me no.