Do I need to pay estimated taxes quarterly if I make enough trading stocks?

I have a full time job and have started trading stocks few months back. Already I have enough realized gains that will force me to pay additional tax. My question is do I need to pay estimated taxes quarterly based on the profits I have made so far or can I wait till the end of the year to pay my taxes.
Any one who has been in this situation, if you can share your experience, it will be greatly appreciated.