I mean, the only thing is if, at the time you make the purchase, you have money in the stock market that's not in an IRA, you should sell that first (assuming it makes sense for the underlying investments, of course). And any year when you are putting money in the stock market, you should be maxing out your IRA first.
Someone can correct me if I'm wrong, but I don't think you can take a tax deduction for selling at a loss in an IRA. That could be extremely relevant for short term speculation like this.
Also, doublecheck what I said about the 5-year rule thing because I'm not sure if you literally have to have had the principal you're selling for 5 years vs. the account being open for 5 years. I've read the latter on a lot of websites but haven't looked at the IRS wording for some time.