Does an individual share of a stock have some kind of unique identifier?
"I agree with the answer by @Michael that this number doesn't exist.  It's hard to see what use it would have and it would be difficult to track. I'm writing a separate answer because I also disagree with the premise of your question:  Individual shares of stock have never to my knowledge had such a number.  Your comment about numbers on stock certificates identifies the certificate document, which will generally represent multiple shares of stock.  That number no more identifies a single share of stock than the serial number on a $10 bill identifies any one of the ten dollars it represents.  Even at the ""collective"" unit of $10, when the bill is eventually replaced with a new one, the new bill has a new number.  No continuity." "There is no unique identifier that exists to identify specific shares of a stock. Just like money in the bank, there is no real reason to identify which exact dollar bills belong to me or you, so long as there is a record that I own X bills and I can access them when I want. (Of course, unlike banks, there is still a 1:1 relationship between the amount I should own and the amount they actually hold). If I may reach a bit, the question that I assume you are asking is how are shared actually tracked, transferred, and recorded so that I know for certain that I traded you 20 Microsoft shares yesterday and they are now officially yours, given that it's all digital. While you can technically try and request a physical share certificate, it's very cumbersome to handle and transfer in that form.  Ownership of shares themselves are tracked for brokerage firms (in the case of retail trading, which I assume is the context of this question as we're discussion personal finance). Your broker has a record of how many shares of X, Y, and Z you own, when you bought each share and for how much, and while you are the beneficial owner of record (you get dividends, voting rights, etc.) your brokerage is the one who is ""holding"" the shares. When you buy or sell a stock and you are matched with a counterparty (the process of which is beyond the scope of this question) then a process of settlement comes into play. In the US, settlement takes 3 working days to process, and technically ownership does not transfer until the 3rd day after the trade is made, though things like margin accounts will allow you to effectively act as if you own the shares immediately after a buy/sell order is filled. Settlement in the US is done by a sole source, the Depository Trust & Clearing Corporation (DTCC). This is where retail and institutional trade all go to be sorted, checked and confirmed, and ultimately returned to the safekeeping of their new owners' representatives (your brokerage). Interestingly, the DTCC is also the central custodian for shares both physical and virtual, and that is where the shares of stock ultimately reside." Nope, think what a nightmare that would be, a bunch of shares would be issued and then sold to tonnes of people, who might sell various partial numbers of them to others, who might buy them and others from 20 others all as part of one order though multiple fills... It would be nuts, and if one were to issue a certificate with the IDs of shares that were carried through such a process the likelihood is the fragmentation would be so great that 100K shares would have consist of almost as many fragments! Imagine a share certificate with 70K IDs/ranges? Yikes!
Unless your brokerage will sell you fractional shares, the most obvious difference (without us knowing the actual identify of the companies) is that with the $260 one, you will have 3 shares plus you will have $220 minus commission left over that you wanted to invest but weren't able to simply because of the mechanics of long division. You could put that $220 into one of the cheaper stocks, but now the multiple commissions will start to eat your returns. My personal opinion is you should go for a low cost index mutual fund or ETF, and wait to pick individual stocks until you have more than $1000 to work with (and even then, probably still go with the low cost index fund) The ownership of the house depends on what the original deed transferring title at the time of purchase says and how this ownership is listed in government records where the title transfer deed is registered. Hopefully the  two records are consistent.  In legal systems that descended from British common law (including the US), the two most common forms of ownership are tenancy in common meaning that, unless otherwise specified in the title deed, each of the owners has an equal share in the entire property, and can sell or bequeath his/her share without requiring the approval  of the others, and joint tenancy with right of survivorship meaning  that all owners have equal share, and if one owner  dies, the survivors form a new JTWROS. Spouses generally own property,  especially the home, in a special kind of JTWROS called tenancy by the entirety. On the other hand, the rule is that unless explicitly specified otherwise, tenancy in common with equal shares is how the owners hold the property. Other countries may have different default assumptions, and/or have multiple other forms of ownership (see e.g. here for the intricate rules applicable in India). Mortgages are a different issue. Most mortgages state that the mortgagees are jointly and severally liable for the mortgage  payments meaning that the mortgage holder does not care who makes the payment but only that the mortgage payment is made in full. If one owner refuses to pay his share, the others cannot send in their shares of the mortgage payment due and tell the bank to sue the recalcitrant co-owner for his share of the payment: everybody is liable (and can be sued) for the unpaid amount, and if the bank forecloses, everybody's share in the property is seized, not just the share owned by the recalcitrant person.  It is, of course, possible to for different co-owners to have separate mortgages for their individual shares, but the legalities (including questions such as whose lien is primary and whose secondary) are complicated. With regard to who paid what over the years of ownership, it does not matter as far as the ownership is concerned. If it is a tenancy in common with equal shares, the fact that the various owners paid the bills (mortgage payments, property taxes, repairs and maintenance) in unequal amounts does not  change the ownership of the property unless a new deed is recorded with the new percentages.  Now, the co-owners may decide among themselves as a matter of fairness that any money realized from a sale of the property should be divided up in accordance with the proportion that each contributed during the ownership, but that is a different issue. If I were a buyer of property titled as tenancy in common, I (or the bank who is lending me money to make the purchase) would issue separate checks to each co-seller in proportion to the percentages listed on the deed of ownership, and let them worry about whether they should transfer money among themselves to make it equitable. (Careful here! Gift taxes might  well be due if large sums of money change hands). A mutual fund makes distributions of its dividends and capital gains, usually once a year, or seminanually or quarterly or monthly etc; it does not distribute any capital losses to its shareholders but holds them for offsetting capital gains in future years, (cf, this answer of mine to a different question). A stock pays  dividends; a stock neither has nor does it  distribute capital gains: you get capital gains (or losses) when you sell the shares of the stock, but these are not called distributions of any kind. Similarly, you incur capital gains or losses when you  redeem shares of mutual funds but these are not called distributions  either. Note that non-ETF mutual fund shares are generally not bought and sold on stock exchanges; you buy shares directly from the fund and you sell shares back (redeem them) directly to the fund.  All of the above transactions are taxable events for the year to you unless the shares are being held in a tax-deferred account or are tax-free for other reasons (e.g. dividends from a municipal bond fund). Having all of the numbers you posted is a start. It's what you need to perform the calculation.  The final word, however, comes from the company itself, who are required to issue a determination on how the spin-off is valued. Say a company is split into two. Instead of some number of shares of each new company, imagine for this example it's one for one. i.e. One share of company A becomes a share each in company B and company C. This tell us nothing about relative valuation, right? Was B worth 1/2 of the original company A, or some other fraction? Say it is exactly a 50/50 split. Company A releases a statement that B and C each should have 1/2 the cost basis of your original A shares. Now, B and C may very well trade ahead of the stock splitting, as 'when issued' shares. At no point in time will B and C necessarily trade at exactly the same price, and the day that B and C are officially trading, with no more A shares, they may have already diverged in price. That is, there's nothing you can pull from the trading data to identify that the basis should have been assigned as 50% to each new share. This is my very long-winded was of explaining that the company must issue a notice through your broker, and on their investor section of their web site, to spell out the way you should assign your basis to each new stock. A company can issue different kinds of shares. For example, some kinds of shares may get preference in dividends or payment in event of (company) bankruptcy. Preferred shares are an example of this. A company might have several kinds of preferred shares and a 'common stock'. Here is a good explanation. See too the Wikipedia article about preferred stock. Toronto-Dominion Bank (TD) is an example of a company that has fourteen different preferred share issues, each with its own listing on the Toronto Stock Exchange (TSE) and symbol. TD has one kind of common stock, which is also listed on the TSE. However, TD common equity trades much more actively than the preferred shares. Remember that preferred stock is a different security type than common stock e.g. common has voting rights, preferred does not. If you had an agreement with your friend such that you could bring back a substantially similar car, you could sell the car and return a different one to him.  The nature of shares of stock is that, within the specified class, they are the same.  It's a fungible commodity like one pound of sand or a dollar bill.  The owner doesn't care which share is returned as long as a share is returned.   I'm sure there's a paragraph in your brokerage account terms of service eluding to the possibility of your shares being included in short sale transactions. A public company should have a link for investor relations, which should help provide a trail of basis if this is a matter of company buyout, takeover, etc.  This gets you close, but if you don't have an exact date, it will just be close, not exact.  One clean way out of this, assuming the goal is to get rid of the stock and move on, is to donate the shares to charity. You will take the present value as a deduction, and be done. You can use a charitable gift fund such as those offered by Schwab or Fidelity, so if say, the shares are worth $20K, and you typically donate $5K per year, the fund lets you do this transaction at once, then send to the charities you wish over the next few years. "That share class may not have a ticker symbol though ""Black Rock MSCI ACWI ex-US Index"" does have a ticker for ""Investor A"" shares that is BDOAX.  Some funds will have multiple share classes that is a way to have fees be applied in various ways.  Mutual fund classes would be the SEC document about this if you want a government source within the US around this. Something else to consider is that if you are investing in a ""Fund of funds"" is that there can be two layers of expense ratios to consider.  Vanguard is well-known for keeping its expenses low."