<prompt> Human: This is a fairly common situation where I live. Some people work for a startup and are blessed quickly by many shares of a successful stock. Others, like me, work for a company for several years and accumulate stock along the way. The stock covers the entire range of cost basis, as the stock has risen along the way. Either way, people end up with a decent amount of net worth, but in a highly concentrated stock position. Most times, the employee has zero experience with managing this risk.There are times where I have lost or regained 40 of my net worth in a year by holding on to this stock. I know others in my situation, ranging from 25K to 2 million.So... Where do I start? I have read about equity collars, exchange funds, completion funds, etc. I am concerned with diversifying without losing my shirt to taxes. Who are reputable experts I can consult with in this field? Do big company wealth management services like Merrill Lynch provide the right type of advice, or is there a more specialized type of advisor for this?tl;dr: I have found myself in a potentially disastrous financial situation where the vast majority of my net worth is tied up in one investment. How do I undo this? Who do I talk to first?Thanks for any advice!Assistant: You cant get out of paying taxes on the profit youve made from the appreciation, but check to see how much is qualified for the long term capital gains rate.If you, for some contractual or tax reason, cannot sell, you can sell calls above the value of the security and use the money to buy puts below the value of the security, effectively locking your stock within a range for no cost other than commissions. This is referred to as a collar.Human: Thanks. Ive read about collars. In my case, I have restricted stocks that have vested over time. As they vested, the company did withhold taxes at whatever cost basis. My older RSUs are still at a low enough basis that if I just went selling those as another commenter suggested, I would would end up with a huge tax burden as I understand, based on my almost complete ignorance on the subject. Collars seem to be able to mitigate this to an extend.  <response>: Just a warning -- a lot of companies in the area specify in your employment agreement that you arent allowed to trade derivatives of the company. Make sure you check before you try anything fancy like that.Definitely talk to a CPA, but youre unlikely to be able to do anything to avoid the tax hit. 