Value of put if underlying stays below strike?
The value at expiration does not depend on the price path for a plain vanilla European or American option. At expiration, the value would simply be: max[K - S_T, 0], where: K is the strike price, and S_T is the underlying price at expiration. $15 - $5 = $10 How did you possibly buy a put for less than the intrinsic value of the option, at $8.25 So we can infer that you would have had to get this put when the stock price was AT LEAST $6.75, but given the 3 months of theta left, it was likely above $7 The value of the put if the price of the underlying asset (the stock ABC) meandered between $5 - $7 would be somewhere between $10 - $8 at expiration. So you don't really stand to lose much in this scenario, and can make a decent gain in this scenario. I mean decent if you were trading stocks and were trying to beat the S&P or keep up with Warren Buffett, but a pretty poor gain since you are trading options! If the stock moves above $7 this is where the put starts to substantially lose value.
"One alternative strategy you may want to consider is writing covered calls on the stock you have ""just sitting there"".  This will allow you to earn a return (the premium from the calls) without necessarily having to give up your holding. As a brief overview, ""options"" are derivatives that give the holder the right (or option) to buy or sell shares at a specified price.  Holders of call options with a strike prike $x on a particular security have the right to purchase that security at the strike price $x.  Conversely, holders of put options with a strike price of $x have the right to sell that security at the strike price $x.  Always on the other side of a call or put option is a person that has sold the option, which is called ""writing"" the option.  If this person writes a call option, then he will be obligated to sell a certain amount of stock (100 shares per contract) at the strike price if that option is exercised.  A writer of a put option will be obligated to by 100 shares per contract at the strike price if that option is exercised. Covered calls involve writing call contracts on stock that you own.  For example, say you own 100 shares of AAPL, and that AAPL is currently trading for $330.  You decide to write a Jan 21, 2012 call on these shares at a strike price of $340, earning you a premium of say $300. Two things can now happen: if the price of AAPL is not at least $340 on January 21, then the options are ""out of the money"" and will expire unexercised (why exercise an option to buy at $340 when you can buy at the currently cheaper market price?).  You keep your AAPL stock plus the $300 premium you earn.  If, however, the price of AAPL is greater than $340, the option will be exercised and you will now be required to sell the shares you own at $340.  You will earn a return of $10/share ($340-$330), plus the $300 premium from the call option.  You still make out in the end, but have unfortunately incurred an opportunity cost, as had you not written the call option you would have been able to sell at the market price, which is higher than the $340 strike price. Covered calls are considered relatively safe and conservative, however the strategy is most effective for stocks that are expected to stay within a relatively narrow price range for the duration of the contract.  They do provide one option of earning additional money on stocks you are currently holding, albeit at the risk of giving up some returns if the stock price rises above the strike price." You have a lot of different questions in your post - I am only responding to the request for how to value the ESPP. When valuing an ESPP, don't think about what you might sell the shares for in the future, think about what the market would charge you for that option today. In general, an option is worth much less than the underlying share itself. For the simplest example, assume you work at a public company, and your exercise price for your options is $.30, and you can only exercise those options until the end of today, and the cost of the shares on the public stock exchange is also $.30. You have the same 'strike price' as everyone else in the market, making your option worth nothing. In truth, holding that right to a specific strike price into the future does give you value, because it means you can realize the upside in share price gains, without risking any money on share losses. So, how do you value the options? If it's a public company with an active options market, you can easily compare your $.30 strike price with the value of call options in the market that have a $.30 strike price. That becomes the value to you of the option (caveat: it is unlikely you can find an exact match for the terms of your vesting period, but you should be able to find a good starting point). If it's a public company without an active options market, you will have to do a bit of estimation. If a current share is worth $.25 (so, close to your strike price), then your option is worth a little bit, but not much. Compare other shares in your industry / company size to get examples of the relative value between an option and a share. If the current share price is worth $.35, then your option is worth about $.05 [the $.05 profit you could get by immediately exercising and selling, plus a bit more for an option on a share that you can't buy in the open market]. If it's a private company, then you need to be very clear on how shares are to be valued, and what methods you have available to sell back to the company / other individuals. You can then consider as per above, how to value the option for a share, vs the share itself. Without a clear way to sell your shares of a private company [ideally through a sale directly back to the company that you are able to force them to agree on; ie: the company will buyback shares at 5x Net income for the previous year, or something like that], then the value of a small number of shares is very nebulous. There is an extremely limited market for shares of private companies, if you don't own enough to exert control. In your case, because the valuation appears to be $2/share [be sure that these are the same share classes you have the option to buy], your option would be worth a little more than $1.70, if you didn't have to wait 4 years to exercise it. This would be total compensation of about $10k, if you were able to exercise today. Many people don't end up working for an early job in their career for 4 years, so you need to consider whether how much that will reduce the value of the ESPP for you personally. Compared with salary of 90k, 10k worth of stock in 4 years may not be a heavy motivating compensation consideration. Note also that because the company is not public, the valuation of $2/share should be taken with a grain of salt. In Australia there are 2 type of warrants (I don't know if it is the same in the US, UK and other countries), the first are trading warrants and the second are instalment warrants. The trading warrants are exactly what it says, they are used for trading. They are similar to option and have calls and puts. As Cameron says, they differ from exchange traded options in that they are issued by the financial companies whereas options are generally written by other investors. Instalment warrants on the other hand are usually bought and sold by investors with a longer term view. There are no calls and puts and you can just go long with them. They are also issued by financial companies, and how they work is best explained through an example: if I was to buy a stock directly say I would be paying $50 per share, however an instalment warrant in the underlying stock may be offered for $27 per warrant. I could buy the warrant directly from the company when it is issued or on the secondary market just like shares. I would pay the $27 per warrant upfront, and then in 2 years time when the warrant expires I have the choice to purchase the underlying stock for the strike price of say $28, roll over to a new issue of warrants, sell it back on the secondary market, or let it expire, in which case I would receive any intrinsic value left in the warrant. You would have noticed that the warrant purchase price plus the strike price adds up to more than the share price ($55 compared to $50). This is the interest component inherent in the warrant which covers the borrowing costs until expiry, when you pay the second portion (the strike price) and receive the underlying shares. Another difference between Instalment warrants and trading warrants (and options) is that with instalment warrants you still get the full dividends just like the shares, but at a higher yield than the shares. "Options are generally viewed as having two types of value: ""Intrinsic value"" and ""time value.""  The intrinsic value is based on the difference between the strike price on the option and the spot price of the underlying.  The time value is based on the volatility of the underlying and the amount of time left until expiration.  As the days pass toward expiration, the time value generally decreases, and the intrinsic value may move up or down depending on the spot price of the underlying. (In theory, time value could increase at some points if the volatility is also rising.) In your case, it looks like the time value is decreasing faster than the intrinsic value is increasing. This may happen because the volatility is also going down (as suggested in the answer by CQM) or may just happen because the time to expiration is getting shorter at equal volatility. As noted by DumbCoder in a comment to the original question, the Black-Scholes formula will give you more analytical insight into this if you're interested." Depending on the structure of you're portfolio, it could be that your portfolio is delta neutral to take advantage of diminishing time value on options, short straddles/strangles would be an example. You said the decision will be made by EOD. If you've made the decision prior to the market close, I'd execute on the closing price.  If you are trading stocks with any decent volume, I'd not worry about the liquidity.  If your strategy's profits are so small that your gains are significantly impacted by say, the bid/ask spread (a penny or less for liquid stocks) I'd rethink the approach. You'll find the difference between the market open and prior night close is far greater than the normal bid/ask. Here's a simple example for a put, from both sides. Assume XYZ stock trades at $200 right now.  Let's say John writes a $190 out of the money put on XYZ stock and sells this put to Abby for the premium, which is say $5. Assume the strike date, or date of settlement, is 6 months from now.  Thus Abby is long one put option and John is short one put option (the writer of the option is short the option). On settlement date, let's assume two different scenarios: (1) If the price of the stock decreases by $50, then the put that Abby bought is 'in the money'. Abby's profit can be calculated as being strike price 190 - current stock price 150 - premium paid 5 = $35 So not including any transaction fees, that is a $35 dollar return on a $5 investment. (2) If the price of the stock increases by $50, then the put that Abby bought is worthless and her loss was 100%, or her entire $5 premium.  For John, he made $5 in 6 months (in reality you need collateral and good credit to be able to write sizable option positions). The risk situation of the put option is the same whether you own the stock or not.  You risk $5 and stand to gain 0 to $250 in the period before expiration (say $50 if the stock reaches $200 and you sell).   Holding the stock or not changes nothing about that.  What is different is the consideration as to whether or not to buy a put when you own the stock.  Without an option, you are holding a $250 asset (the stock), and risking that money.  Should you sell and miss opportunity for say $300? Or hold and risk loss of say $50 of your $250?  So you have $250 at risk, but can lock in a sale price of $245 for say a month by buying a put, giving you opportunity for the $300 price in that month.  You're turning a risk of losing $250 (or maybe only $50 more realistically) into a risk of losing only $5 (versus the price your stock would get today).