if you sell some tickers settled before 12/31 for a loss, then file tax
return after 45 days to show that it was (or they were) no wash sale. But I
understand F1 students will like to file tax as early as possible to get
early refund, while full-time workers like to wait until April 14 to file
and delay paying owed taxes.
So, if you are such F1 students, LZ's suggestion is good for you to realize
loss in November and get done with it. If you know you will owe tax, you
can file tax return later near April 15, so it doesn't matter. But of course
these are all assuming no wash sale. If you do buy back and therefore a
wash sale, you must defer you loss to 2015 in any case.
Also, if you know you have huge capital gain profit as of 12/31, you better
pay estimated taxes by 1/15 to be safe that you don't need to pay penalty.