Application deadlines for math phd program on a rolling basis I am interested in math phd programs for Algebraic Topology.  Most of the programs that I am interested in have deadlines in December and January.  I was under the impression that one generally submitted the application earlier, and early enough that people who take the subject in October don't get to see their scores before they are sent to colleges.

Is this because the deadlines are on a rolling basis?
In the U.S., mathematics Ph.D. programs usually do not have rolling admissions, and I do not think any of the top programs do.  Some people do submit applications at the last minute, but many people submit earlier because they have completed their application materials well in advance.  For example, if you'd like to get feedback on your application from other people, or if you are planning to provide it to letter writers in advance, then you shouldn't wait until the deadline.  Another reason to complete everything early is if you need similar materials for fellowship applications (e.g., the NSF deadline is in October), or if you want to get it out of the way before you become really busy at the end of the semester.


  I was under the impression that one generally submitted the application earlier, and early enough that people who take the subject in October don't get to see their scores before they are sent to colleges.


I don't have any statistics, but my impression is that most people who take the October GRE haven't taken it before.  (They waited until their last year, but missed the summer deadline for the September test.)  In that case, these are their only scores, so there's no benefit to waiting to see how they did.  Even if they score lower than expected, that alone is not a compelling reason to change where they apply.