Yesterday my reputation on Math.SE was around 2450 points. Today I logged in and I saw, unexpectedly, that it is 3913. I have not gained any reputation since yesterday, according to my profile page. So why did I receive this massive increase in points?
The reputation for an upvote on a question has been changed from +5 to +10, as announced in this blog post: We’re Rewarding the Question Askers. (So now reputation gained from an upvote on a question is the same as the reputation gained from an upvote on an answer.)
Here is a similar question on Meta Stack Exchange: My reputation suddenly raised by 10k!
Since some users might be interested in discussing this recent change further, it might be useful to point out there are several related discussions on Meta Stack Exchange, such as: