Where can I find the nominal price of a stock prior a split into multiple companies?
When Hewlett Packard split they changed their name to HP Inc. and spun off Hewlett Packard Enterprise as a new corporation. This means HP Inc. has the same stock history and ticker (HPQ) as Hewlett Packard did so that's the one you want to search for. As you noticed this also means it's impossible to search for old Hewlett Packard's stock performance alone. One free service that seems to show the unadjusted historical stock price of HPQ is Google finance: https://www.google.com/finance?q=NYSE%3AHPQ Yahoo Finance provides the proper closing price.  HP's historical data around the split date can be found here. The open, high and low of the day are wrong prior the split, but the closing price is right and for HP, it was $26.96 USD.  The next day the closing price was $13.83 USD.
"Debt is nominal, which means when inflation happens, the value of the money owed goes down.  This is great for the borrower and bad for the lender. ""Investing"" can mean a lot of different things.  Frequently it is used to describe buying common stock, which is an ownership claim on a company.  A company is not a nominally fixed asset, by which I mean if there was a bunch of inflation and nothing else happened (i.e., the inflation was not the cause or result of some other economic change) then the nominal value of the company will go up along with the prices of other things. Based on the above, I'd say you are incorrect to treat debt and investment returns the same way with respect to inflation.  When we say equity returns 9%, we mean it returns a real 7% plus 2% inflation or whatever.  If the rate of inflation increased to 10% and nothing else happened in the economy, the same equity would be expected to return 17%.  In fact, the company's (nominally fixed) debts would be worth less, increasing the real value of the company at the expense of their debt-holders. On the other hand, if we entered a period of high inflation, your debt liability would go way down and you would have benefited greatly from borrowing and investing at the same time.   If you are expecting inflation in the abstract sense, then borrowing and investing in common stock is a great idea. Inflation is frequently the result (or cause) of a period of economic trouble, so please be aware that the above makes sense if we treat inflation as the only thing that changed.  If inflation came about because OPEC makes oil crazy expensive, millennials just stop working, all of our factories got bombed to hades, or trade wars have shut down international commerce, then the value of stocks would most definitely be affected.  In that case it's not really ""inflation"" that affected the stock returns, though." During a stock split the only thing that changes is the number of shares outstanding.  Typically a stock splits to lower its price per share.  Sometimes if a company's value is falling it will do a reverse split where X shares will be exchanged for Y shares.  This is typically done to avoid being de-listed from an exchange if the price per share falls below a certain threshold, usually $1.  Again the only thing changing is the number of shares outstanding.  A 20 for 1 reverse split means for every 20 shares outstanding the shareholder will be granted one new share. Example X Co. has 1,000,000 shares outstanding for a price of $100 per share.  It does a 1 for 10 split.  Now there are 10,000,000 shares outstanding for a price of $10 per share. Example Y Co has 1,000,000 shares outstanding for a price of $1 per share.  It does a 10 for 1 reverse split.  Now there are 100,000 shares outstanding for a price of $10. Quickly looking at the news for ASTI it looks like it underwent a 20 for 1 reverse split.  You should probably look at your statements and ask your broker how the arithmetic worked in your case. Investopedia links for Reverse Stock Split and Stock Split One way that is common is to show the value over time of an initial investment, say $10,000.  The advantage of this is that it doesn't show stock price at all, so handles splits well.  It can also take into account dividend reinvestment.  Fidelity uses this for their mutual funds, as can be seen here.  Another option would be to compute the stock price as if the split didn't happen.  So if a stock does a 2:1 split, you show double the actual price starting at that point. You'd likely be subject to a lock-up period before you could sell the shares along with possibly having other rules about how you could sell your shares as you'd likely be seen as an insider that may have information that gives you an unfair advantage for selling the stock possibly. Depending on how far in advance you hold the shares, you may or may not have adjustments in the valuation and number of shares as some companies may do a split or reverse split when preparing for an IPO. A company I worked for in the late 1990s had an IPO and my stock options had a revised strike price because of a reverse stock split that was done prior to the IPO. A stock market is just that, a market place where buyers and sellers come together to buy and sell shares in companies listed on that stock market. There is no global stock price, the price relates to the last price a stock was traded at on a particular stock market. However, a company can be listed on more than one stock exchange. For example, some Australian companies are listed both on the Australian Stock Exchange (ASX) and the NYSE, and they usually trade at different prices on the different exchanges. Also, there is no formula to determine a stock price. In your example where C wants to buy at 110 and B wants to sell at 120, there will be no sale until one or both of them decides to change their bid or offer to match the opposite, or until new buyers and/or sellers come into the market closing the gap between the buy and sell prices and creating more liquidity. It is all to do with supply and demand and peoples' emotions. I'm a finance newb....sorry ahead of time for everyone slamming their heads against the the wall.  I'm going to go ahead and possibly answer my own question. Do I just go back 4 months at a time from their 10K and record the stock price on that date? A rough estimate of the money you'd need to take a position in a single stock would be: In the case of your Walmart example, the current share price is 76.39, so assuming your commission is $7, and you'd like to buy, say, 3 shares, then it would cost approximately (76.39 * 3) + 7 = $236.17. Remember that the quoted price usually refers to 100-share lots, and your broker may charge you a higher commission or other fees to purchase an odd lot (less than 100 shares, usually).  I say that the equation above gives an approximate minimum because  However, I second the comments of others that if you're looking to invest a small amount in the stock market, a low cost mutual fund or ETF, specifically an index fund, is a safer and potentially cheaper option than purchasing individual stocks. Since you asked about Apple, and I happen to have two positions -   This is what happened. I was long the $500, short the $600, in effect, betting Apple would recover from its drop from $700 down to $450 or so. Friday, my target was to hope that Apple remain above $600, but not really caring how much it went over. Now, post split, the magic number is $85.71. My account shows the adjusted option pricing, but doesn't yet show AAPL's new price.