Exactly what the title says.
If bitcoin dropped to the price of a dollar (which we hope it never will), what would you do? Buy more and hold, sell? Buy a promising altcoin like ETH?
I personally would buy more bitcoin.
I have to say as it descended from 450 to 400 . I would buy. When it got to 300 I would buy again. When it got to 200 I would buy again. When it got to 100 I would buy again.
Same thing at 50. Same thing at 25. Same thing at 10. Same thing at 5 . Lastly one more time at 1.
All actions above are based on the idea that the drop takes 10 days or so. With no apparent reason ie some one did not figure a way to hack the code and turn coins into worthless junk.
I also think 100 was low enough for the ops question.