Should I dump $7,400 in Our Roth IRAs today or wait until end of the year?

27 [M&F] looking to maxing our Roths this year and every year in the future. I maxed mine last year and started my wife’s this year. I scaled back investing each month to save for a house down payment but changed my mind and want to max the accounts. Is there any reason I should hold off until the end of the year or just slam $3,700 into each account today to max them out?