Would cross holding make market capitalization apparently more?
I started to work out, step by step, why this doesn't work, but the scenario is too convoluted to make that helpful.  Basically, you're making mistakes in some or all of the following spots: Initially, Each company has 10k shares. Company B has $500k money and possibly other assets. Every company has stated purpose. It can't randomly buy shares in some other firm.   Company A issued 5k new shares, which gives it $500k money. Listed companies can't make private placements without regulatory approvals. They have to put this in open market via Public issue or rights issue. Company B does the same thing, issuing 5k shares for $500k money. Company A bought those 5k shares using the $500k it just got There is no logical reason for shareholder of Company B to raise 5K from Company A for the said consideration. This would have to increase.
Yes. You incur income tax on the RSU on they date they vest. At this point you own the actual shares and you can decide to sell them or to hold them. If you hold them for the required period, and sell them later, the difference between your price at vesting and the sales price would be taxed as long term capital gains. Caution: if you decide to hold, you are still liable to pay income tax in the year they vest. You have to pay taxes on income that you haven't made yet. This is fairly dangerous: if the stock goes down, you may lose a lot of this tax payment. Technically you could recover some of this through claiming capital losses, but that this is severely restricted: the IRS makes it much easier to increase taxes through gains than reducing taxes through losses. "Do I make money in the stock market from other people losing money? Not normally.* The stock market as a whole, on average, increases in value over time. So if we make the claim that the market is a zero-sum game, and you only make money if other people lose money, that idea is not sustainable. There aren't that many people that would keep investing in something only to continue to lose money to the ""winners."" The stock market, and the companies inside it, grow in value as the economy grows. And the economy grows as workers add value with their work.  Here's an analogy: I can buy a tree seed for very little and plant it in the ground. If I do nothing more, it probably won't grow, and it will be worth nothing. However, by taking the time to water it, fertilize it, weed it, prune it, and harvest it, I can sell the produce for much more than I purchased that seed for. No one lost money when I sell it; I increased the value by adding my effort.  If I sell that tree to a sawmill, they can cut the tree into usable lumber, and sell that lumber at a profit. They added their efforts and increased the value.  A carpenter can increase the value even further by making something useful (a door, for example). A retail store can make that door more useful by transporting it to a location with a buyer, and a builder can make it even more useful by installing it on a house.  No one lost any money in any of these transactions. They bought something valuable, and made it more valuable by adding their effort.  Companies in the stock market grow in value the same way. A company will grow in value as its employees produce things. An investor provides capital that the company uses to be able to produce things**, and as the company grows, it increases in value. As the population increases and more workers and customers are born, and as more useful things are invented, the economy will continue to grow as a whole.  * Certainly, it is possible, even common, to profit from someone else's loss.  People lose money in the stock market all the time.  But it doesn't have to be this way.  The stock market goes up, on average, over the long term, and so long term investors can continue to make money in the market even without profiting from others' failures. ** An investor that purchases a share from another investor does not directly provide capital to the company.  However, this second investor is rewarding the first investor who did provide capital to the company.  This is the reason that the first investor purchased in the first place; without the second investor, the first would have had no reason to invest and provide the capital.  Relating it to our tree analogy: Did the builder who installed the door help out the tree farmer?  After all, the tree farmer already sold the tree to the sawmill and doesn't care what happens to it after that.  However, if the builder had not needed a door, the sawmill would have had no reason to buy the tree." "It is important to remember that the stock price in principle reflects the value of the company, so the market cap should drop upon issuance of the the dividend. However, the above reasoning neglects to consider taxes, which make the question a bit more interesting. The key fact is that different investors are going to get taxed on the dividend to varying degrees, ranging from 20% for qualified dividends in the USA for a high-income individual in a taxable account (and even worse for non-qualified dividends) to 0% for tax-exempt nonprofits, retirement accounts, and low-income individuals. The high-tax investors are going to be a bit averse to paying tax on that dividend, whereas the tax-free investors are not. Hence in a tax-rational market the tax-free investors are going to be the ones buying right before a dividend and the tax-paying investors will be buying right afterwards. Tax-exempt investors could in principle make some amount of money buying dividends to keep them off the tax-paying investors' books.  (Of course, the strategy could backfire if too many people did it all at once.) That said, the tax-payers have the tax disincentive to prevent them from fully exploiting the opposite strategy of selling just before a dividend.  In particular, they are subject to capital gains tax when they sell at a profit (unless they have enough compensating capital losses), and it is to their after-tax profit to defer taxation by not trading. That said, the stock market has well-known irrationality when it comes to considering tax consequences, so logic based on assumed rationality of the market does not always apply to the extent one would expect.   The foremost example of tax-irrationality is the so-called ""dividend paradox"", which basically states that corporations should favor stock buybacks (or perhaps loan repayment) to the complete exclusion of dividends because capital gains are taxed less harshly than dividends in a variety of ways, some of which are subtle: 1) Historically (although not currently in the USA for qualified dividends) the tax rate was higher for dividends.  (In Canada, for example, dividends are taxed at twice the rate of capital gains.) 2) If you die holding appreciated stock then you (meaning your heirs) completely escape US the capital gains tax on the accrual during your lifetime. 3) Capital gains tax can be deferred by simply not selling.  In comparison to dividends, this is roughly equivalent to getting a tax-free loan from the government which is invested for profit and paid at a later date after inflation has eaten away at the real value of the loan.  For example, if all your stock investments increase by 10%/year but you sell every year, in a high-tax bracket situation you're total after-tax return will be only 8% per year.  In contrast, if you hold the same investments for many many years and then sell, your total return will be nearly 10% per year, because you only pay 20% once (at the end). 4) A capital gain can often be neutralized by a capital loss in another stock, so that no tax results.  If you loose money on a stock that is paying dividends, you're still going to have to pay tax on that dividend.  There are companies that borrow money to pay out that taxable-dividend each quarter, which seems like gross tax malpractice on the part of the CFO. (If the dividend paradox doesn't make sense, first consider the case that you owned ALL the shares of a company.  It wouldn't matter to you at all on a pre-tax basis whether you got a $1000 company buyback or a $1000 dividend, because after the buyback/dividend you'd still own the entire company and $1000.  The number of shares would be reduced, but objecting that you owned fewer shares after the buyback would be like saying you have become shorter if your height is measured in inches rather than centimeters.) [Of course, in the case of many shareholders you can get burned by failing to sell into the buyback when the share price is too high, but that is another matter.]" "Sometimes 403b's contain annuities or other insurance related instruments.  I know that in many New York schools the local teacher unions administer the 403b plan, and sometimes choose proprietary investments like variable annuities or other insurance products. In New York the Attorney General sued and settled with the state teacher's union for their endorsement of a high cost ING 403b plan -- I believe the maintenance fees were in excess of 3%/year!  In a tax deferred plan like a 401k, 403b or 457 plan, the low risk ""insurance fund"" is generally a GIC ""Guaranteed Investment Contract"". A GIC (aka ""Stable Value Fund"") is sort of cross between a CD and a Money Market fund. It's used by insurance companies to raise short term capital. GICs usually yield a premium versus a money market and are a safe investment. If your wife is in a 403b with annuities or other life-insurance tie ins other than GICs, make sure that you understand the fee structure and ask lots of questions." Is this a time of day effect by using, e.g. closing prices, in markets that close at different times?  If so, you can mitigate this by looking at returns over longer periods (weekly, monthly or quarterly).  If the cross-listed equities are showing consistently different returns at the exact same time, then you should be more concerned in figuring out how to trade the arbitrage rather than estimating a beta. Every time you buy or sell a share for some price, somebody must have thought that that was exactly the right moment to sell or buy that share at that price (and to trade with you). Every time a trade is made, both sides think they are doing the smart thing. Most of the time, one will turn out to be wrong, the other right. Nothing in your proposed method of trading explains why you would be the side that was right more often. So they'll probably even out. Or maybe there are people in the market who actually do have a slightly better than average method, and you'll be wrong somewhat more often than right. Each trade has transaction costs. If you simply hang on to your shares, that's more or less the same as evening out good trades and bad trades, but without the transaction costs. "When you look at those results you'll see that it lists the actual market cap for the stocks.  The ones on the biggest price move are usually close the the $1B capitalization cut-off that they use. (The don't report anything with less than $1B in capitalization on these lists.)  The ones on the biggest market cap are much larger companies. So, the answer is that a 40% change in price on a company that has $1B capitalization will be a $400M change in market cap.  A 4% change on a company with $100B capitalization will be a $4B change in market cap.  The one that moved 40% will make the ""price"" list but not the market cap list and vice versa." You are assuming the price increase will continue. The people selling are assuming that the price increase will not continue.  Ultimately that's what a share transaction is: one person would rather have the cash at a particular price / time, and one person would rather have the share.