Utilize your financial knowledge, give your answer or opinion to the input question or subject . Answer format is not limited.

Is it accurate to say that if I was to trade something, my probability of success can't be worse than random?
In theory, in a perfect world, what you state is almost true. Apart from transaction fees, if you assume that the market is perfectly efficient (ie: public information is immediately reflected in a perfect reflection of future share value, in all share prices when the information becomes available), then in theory any transaction you would choose to take is opposed by a reasonable person who is not taking advantage of you, just moving their position around. This would make any and all transactions completely reasonable from a cost-benefit perspective.  ie: if the future value of all dividends to be paid by Apple [ie: the value of holding a share in Apple] exactly matches Apple's share price of $1,000, then buying a share for $1,000 is an even trade. Selling a share for $1,000 is also an even trade. Now in a perfectly efficient market, which we have assumed, then there is no edge to valuing a company using your own methods. If you take Apple's financial statements / press releases / reported information, and if you apply modern financial theory to evaluate the future dividends from Apple, you should get the same $1,000 share price that the market has already arrived at. So in this example, why wouldn't you just throw darts at a printout of the S&P 500 and invest in whatever it lands on? Because, even if the 'perfectly efficient market' agrees on the true value of something, different investments have different characteristics. As an example, consider a simple comparison of corporate bonds: Corporations make bond offerings to the public, allowing individual investors to effectively lend money to the corporation, for a future benefit. For simplicity, assume a bond with a 'face value' (the amount to be repaid to the investor on maturity) of $1,000 has these 3 defining characteristics: (1) The price [What the investor pays to acquire it]; (2) Interest payments [how much, if any, the corporation will pay to the investor before maturity, and when those payments will be made]; and (3) a bond rating [which is a third party assessment of how risky the bond is, based on the 'health' of the corporation]. Now if the bond rating agency is perfect in its risk assessment, and if the price of all bond's is fair, then why does it matter who you loan your money to? It matters because different people want different things out of their investments. If you are waiting to make a down payment on a house next year, then you don't want risk - you want to be certain that you will get your cash back, even if it means lower returns. So, even though a high-risk bond may be perfectly priced, it should only be bought by someone willing to bear that risk. If you are retired, and you need your bonds to pay you interest regularly as your sole source of income, then of course a zero-coupon bond [one that pays no interest] is not helpful to you. If you are young, and have a long time to invest, then you may want risk, because you have time to overcome losses and you want to get the most return possible. In addition, taxes are not universal between all investors. Some people benefit from things that would be tax-heavy to their neighbors. For example in Canada, there is a 'dividend tax credit' which reduces the taxes owing on dividends received by a corporation. This credit exists to prevent 'double-taxation', because otherwise the corporation would pay its ~30% of tax, and then a wealthy investor would pay another ~45% of tax. Due to the mechanics of how the credit is calculated, however, someone who makes less money, gets an even lower tax bill than they normally would. This means that someone making under the top tax bracket in Canada, has a tax benefit by receiving dividends. This means that while 2 stocks may be both fairly priced, if one pays dividends and the other doesn't [ie: if the other company instead reinvests more heavily in future projects, creating even more value for shareholders down the road], then someone in the bottom tax brackets may want the dividend paying stock more than the other. In conclusion: Picking investments yourself does require some knowledge to prevent yourself from making a 'bad buy'; this is because the market is not perfectly efficient. As well, specific market mechanics make some trades more costly than they should be in theory; consider for example transaction fees and tax mechanics. Finally, even if you assume that all of the above is irrelevant as a theoretical idea, different investors still have different needs. Just because $1,000,000 is the 'fair' price for a factory in your home town, doesn't mean you might as well convert your retirement savings to buy it as your sole asset.