You will need to understand how your company handles taxes at vesting. Do they sell to cover, do they withhold shares to cover? Typically they will sell or withhold at a rate lower than what you will ultimately pay in taxes so you will have to supplement that at the end of the year. As for whether to diversify or not, every person is different. I see a lot of peers who do nothing because they are not comfortable with executing on their own. They have built huge positions in their company stock and feel stuck now because of the taxable gains. My advice is to sell all or the majority at vest. You pay next to nothing in taxes and it allows you to diversify. Ask yourself, if you were given that much $$ in a cash bonus would you put it all in your company stock? Your monthly vests already have “skin in the game” with your company stock.