I have some browser tabs that have been open for several days.
A few of them show my reputation as either 2221 or 2231.*
My rep is currently 2165, for a drop of 66 from the high-water mark.
My # of posts edited and my progress toward earning a “Sportsmanship” badge
also went down.
__________
* I believe that I most recently refreshed these tabs
between 2016‑08‑18 04:00 and 2016‑08‑18 06:15;
i.e., a little under three days ago.
Of course the reputation score in the top bar may have updated since then.
I seem to recall that, if you (gain or) lose a lot of rep because a user was deleted (or because of voting fraud), you get an annotation to that effect in the “reputation” tab of your user profile page. I don’t have anything like that. My reputation history shows a delta of +9 (one upvote and one down) in the past four days. This leaves an unexplained drop of 75.
From the “answers” tab I see that my answer to What is the next number in the series : 3, 24, 75, 175, 342, ?, with a score of 1, was deleted at 04:05 (on 2016‑08‑18):
(Actually, it was the question that was deleted.) This explains 10 points (and the other statistics). If the vote breakdown on that answer was $\Large\frac{\color{green}{+9}}{\color{red}{-8}}$, that would explain $90-16=74$ points. $\Large\frac{\color{green}{+7}}{\color{red}{-6}}~\color{green}{\checkmark}$ would explain $70-12+15=73$ points, but I really doubt that either of those happened.
This question may appear to be a duplicate of Disappearing reputation, but the answer there was that question(s) (where the OP got rep from answer(s)) had been deleted. I have investigated that avenue and pretty much ruled it out.
I presume that, if there had been a widespread glitch, multiple people would have been affected, and this issue would have been raised here (in meta) by now; but I don’t see it. Can anybody (presumably somebody with privileges) explain what happened to my reputation?