Also keep in mind,
that $300k may balance out with any Short Term Capital Gains in the future.
I had a loss when i was younger, and kept carrying it over over minus $3k per year as i saved more and more and invested more and more, and that Capital Loss was canceled out quickly as I made a lot of money from short term investments especially if you are into Short term Capital Gains.
Or it is now a new investment option to you, as the government has full taxes on it discouraging it's public use to average investors (unless you have capital loss carry over, or day trade.)
Like buying HAUP at $0.70, and selling at $1.13 within two weeks, making 61% profit of your investment in two weeks. (Research, then buy low, sell high, with emotionless trading for short term Capital gains, same goes for long term).
Ordinary taxes on short term Capital Gains= 0%. Because of the Capital loss carry over from year to year cancels out all short term Capital Gains also.
Disclaimer: You may lose money just as quickly, but don't fear to practice the skills necessary to prevent losses..and you'll make money. Greater the Risk, Greater the Reward or Loss. But at least your big rewards aren't taxed greatly for it with Capital Loss Carryover.