Which one is better for an undecided major?
Which cluster were you accepted to for COSMOS? If you are going to Awesomemath program in order to help with math competitions, it’s very difficult to stand out with those competitions unless you’re at the USAMO/USAJMO level. However, math is a great fundamental skill that helps for almost all majors. With COSMOS, you may not learn as much math, but letters of recommendation from faculty and the experience of being in a college campus under a residential setting can’t hurt your chances.