Do the tax consequences make it worth it for me to hold ESPP stock?
To try to answer the three explicit questions: Every share of stock is treated proportionately: each share is assigned the same dollar amount of investment (1/176th part of the contribution in the example), and has the same discount amount (15% of $20 or $25, depending on when you sell, usually). So if you immediately sell 120 shares at $25, you have taxable income on the gain for those shares (120*($25-$17)). Either selling immediately or holding for the long term period (12-18 mo) can be advantageous, just in different ways.   Selling immediately avoids a risk of a decline in the price of the stock, and allows you to invest elsewhere and earn income on the proceeds for the next 12-18 months that you would not otherwise have had.  The downside is that all of your gain ($25-$17 per share) is taxed as ordinary income.   Holding for the full period is advantageous in that only the discount (15% of $20 or $25) will be taxed as ordinary income and the rest of the gain (sell price minus $20 or $25) will be taxed at long-term capital gain tax rates, which generally are lower than ordinary rates (all taxes are due in the year you do sell).  The catch is you will sell at different price, higher or lower, and thus have a risk of loss (or gain). You will never be (Federally) double taxed in any scenario.  The $3000 you put in will not be taxed after all is sold, as it is a return of your capital investment.  All money you receive in excess of the $3000 will be taxed, in all scenarios, just potentially at different rates, ordinary or capital gain.  (All this ignores AMT considerations, which you likely are not subject to.) I think people in general tend to unnecessarily over-complicate this issue.  Here's what I think you should do in any situation like this: First and foremost, put all tax considerations aside and decide whether it makes sense to sell the stock now or hold on to it for the long term based on its merits as an investment.  Tax considerations have absolutely nothing to do with whether the stock is a good investment.  If you consider all non-tax factors and decide to hold on to it for the long term, then you can use the tax considerations as a very minor input to how long you should hold it - in other words, don't set your time horizon to 17.5 months if waiting another 2 weeks gives you better tax treatment. You're going to pay taxes on your gains no matter what.  The only difference is whether you pay capital gains tax or income tax.  Granted, the income tax rate is higher, but wouldn't it suck if you pay a LOT less tax only because you have a LOT less value in your stock? So to answer your question - I would say, absolutely not, tax consequences do not make it worthwhile to hold on to your ESPP shares.  If you decide to hold on to your ESPP for other reasons (and they better be good ones to put that much free profit at risk), only then should you look at the tax consequences to help fine-tune your strategy. Your gain is $1408. The difference between 32% of your gain and 15% of your gain is $236.36 or $1.60 per share. If you sell now, you have $3957.44 after taxes.  Forget about the ESPP for a moment. Are you be willing to wager $4000 on the proposition that your company's stock price won't go down more than $1.60 or so over the next 18 months? I've never felt it was worth it. Also, I never thought it made much sense to own any of my employer's stock. If their business does poorly, I'd prefer not to have both my job and my money at risk. If you sell now: Now assuming you hold for 18 months, pay 15% capital gains tax, and the stock price drops by $1.60 to $23.40:
There's a lot of hype about HFT. It involves computers doing things that people don't really understand and making a bunch of rich guys a bunch of money, and there was a crisis and so we hate rich wall street guys this year, and so it's a hot-button issue. Meh. There's some reason for concern about the safety of the markets, but I think there's also a lot more of people trying to sell you a newspaper. Remember that while HFT may mean there are a lot of trades, the buying and the selling add up to the same thing. Meanwhile, people who buy stock to hold on to it for significant periods of time will still affect the quantity of stock out there on the market, applying pressure to the price, buying and selling at the prices that they think the security is worth.  As a result, it's unlikely that high-frequency trading moves the stock price very far from the price that the rest of the market would determine for very long; if it did, the lower-frequency traders could take advantage of it, buying if it's too low and selling if it's too high. How long do you plan to hold a stock? If you're trying to do day-trading, you might have some trouble; these people are competing with you to do the same thing, and have significant resources at their disposal. If you're holding onto your stock for years on end (like you probably should be doing with most stock) then a trivial premium or discount on the price probably isn't going to be a big deal for you. I see several interesting statement in your question.  A. my only income is from my Employer B. I also receive employer stock (ESPP, RSU, NSO). However, employer withholds taxes for these stock transactions through my broker (I see them broken down on my W2).  C. I have been subject to Alternative Minimum Tax. A implies a simple tax return. B and C tell the opposite story. In fact if B is not done correctly The amount withheld due to payroll may be perfect but the under withholding could be due to the ESPP's, RSUs and NSOs.  The AMT can throw everything else out the window.  If a person has a very simple tax situation: Income doesn't change a lot from paycheck to paycheck; they take the standard deduction; the number of exemptions equals the number of people in the family. Then the withholding is very close to perfect.  The role of the exemptions on the W-4 is to compensate for situations that go above the standard deduction. The role of extra withholding is when the situation requires more withholding due to situations that will bring in extra income or if the AMT is involved. Stock awards by employers are treated and taxed as salary. I.e.: you pay ordinary rate income tax, FICA taxes, State taxes etc. The fact that you got your salary in shares and not cash is irrelevant for tax purposes. Once you got the shares and paid your taxes on them, the treatment is the same as if you got the salary and immediately bought the shares. Holding period for capital gains tax purposes starts at the time you paid your taxes on the award, which is the time at which you get full ownership (i.e.: vesting time, for the restricted stocks). When you sell these stocks - you treat the sale as any other stock sale: you check the holding period for capital gains tax rates, and you do not pay (or get refund) any FICA taxes on the sales transaction. So bottom line: You got $10K salary and you bought $10K worth of company stock, and you sold it at $8K half a year later. You have $10K wages income and $2K short term capital loss. Note that you're asking about withholding, not about taxing.  Withholding doesn't mean this is exactly the tax you'll pay: it means they're withholding a certain amount to make sure you pay taxes on it, but the tax bill at the end of the year is the same regardless of how you choose to do the withholding.  Your tax bill may be higher or lower than the withholding amount. As far as tax rate, that will be the same regardless - you're just moving the money from one place to the other.   The only difference would be that your tax is based on total shares under the plan - meaning that if you buy 1k shares, for example, at $10, so $1,500 discounted income, if you go the payroll route you get (say) $375 withheld.  If you go the share route, you either get $375 worth of stock (so 38 shares) withheld (and then you would lose out on selling that stock, meaning you don't get quite as much out of it at the end) or you would ask them to actually buy rather more shares to make up for it, meaning you'd have a slightly higher total gain.  That would involve a slightly higher tax at the end of it, of course. Option 1:  Buy and then sell $10000 worth, share-based withholding.  Assuming 15% profit, and $10/share at both points, then buy/sell 1000 shares, $1500 in profit to take into account, 38 shares' worth (=$380) withheld.  You put in $8500, you get back $9620, net $1120.   Option 2:  Buy and then sell $13500 worth, share based withholding.  Same assumptions.  You make about $2000 in pre-tax profit, meaning you owe about $500 in tax withholding.  Put in $11475, get back $13000, net $1525.  Owe 35% more tax at the end of the year, but you have the full $1500 to spend on whatever you are doing with it. Option 3:  Buy and then sell $1000 worth, paycheck withholding.  You get the full $10000-$8500 = $1500 up front, but your next paycheck is $375 lighter.  Same taxes as Option 1 at the end of the year. "Once again I offer some sage advice - ""Don't let the tax tail wag the investing dog."" Michael offers an excellent method to decide what to do. Note, he doesn't base the decision on the tax implication.  If you are truly indifferent to holding the stock, taxwise, you might consider selling just the profitable shares if that's enough cash. Then sell shares at a loss each year if you have no other gains. That will let you pay the long term gain rate on the shares sold this year, but offset regular income in years to come. But. I'm hard pressed to believe you are indifferent, and I'd use Michel's approach to decide.  Updated - The New Law is simply a rule requiring brokers to track basis. Your situation doesn't change at all. When you sell the shares, you need to identify which shares you want to sell. For older shares, the tracking is your responsibility, that's all." Usually the amount of the ESPP stocks is very small compared to the overall volume of the trading, so it shouldn't matter. But check if for your company it not so (look at the stock history for the previous ESPP dates, and volumes). Here is how it should look: 100 shares of restricted stock (RSU) vest. 25 shares sold to pay for taxes. W2 (and probably paycheck) shows your income going up by 100 shares worth and your taxes withheld going up by 25 shares worth. Now you own 75 shares with after-tax money. If you stop here, there would be no stock sale and no tax issues.  You'd have just earned W2 income and withheld taxes through your W2 job. Now, when you sell those 75 shares whether it is the same day or years later, the basis for those 75 shares is adjusted by the amount that went in to your W2.   So if they were bought for $20, your adjusted basis would be 75*$20. (I'm assuming the tag of United-states is accurate) Yes, the remaining amount is tax free -- at the current price.  If you sell at exactly the original price, there is no capital gain, no capital loss.  So you've already payed the taxes. If you sell and there is a capital gain of $3000, then you will pay taxes on the $3000.  If 33% is your marginal tax rate, and if you held the stock for less than a year, then you will keep $7000 and pay taxes of $1000.  Somehow, I doubt your marginal tax rate is 33%. If you hold the stock for a year after eTrade sold some for you to pay taxes, then you will pay 15% on the gain -- or $450. eTrade sold the shares to pay the taxes generated by the income.  Yes, those shares were considered income.  If you sell and have a loss, well, life sucks.  However, if you sell something else, you can use the loss to offset the other gain.  So if you sell stock A for a loss of $3000, and sell stock B at a gain of $4000, then you pay taxes on the net of $1000.