In general: diversify as much as is prudent considering the taxes, your financial situation & your downside risk. Consider long-term vs short term capital gain

In general: diversify as much as is prudent considering the taxes, your financial situation & your downside risk. Consider long-term vs short term capital gains, but if the stock volatility is higher than the difference (and the difference is meaningful to your financial health) you may still want to sell at the higher tax rate. If you are in high-interest (credit card, payday loan) style debt, you almost always want to sell and retire that debt; nothing can beat that.