Offer your thoughts or opinion on the input financial query or topic using your financial background.

Why is day trading considered riskier than long-term trading?
Largely, because stock markets are efficient markets, at least mostly if not entirely; while the efficient market hypothesis is not necessarily 100% correct, for the majority of traders it's unlikely that you could (on the long term) find significant market inefficiencies with the tools available to an individual of normal wealth (say, < $500k). That's what frequent trading intends to do: find market inefficiencies.  If the market is efficient, then a stock is priced exactly at what it should be worth, based on risk and future returns.  If it is inefficient, then you can make more money trading on that inefficiency versus simply holding it long.  But in stating that a stock is inefficient, you are stating that you know something the rest of the market doesn't - or some condition is different for you than the other million or so people in the market.  That's including a lot of folks who do this for a living, and have very expensive modelling software (and hardware to run it on).  I like to think that I'm smarter than the far majority of people, but I'm probably not the smartest guy in the room, and I certainly don't have that kind of equipment - especially with high frequency trading nowadays. As such, it's certainly possible to make a bit of money as a trader versus as a long-term investor, but on the whole it's similar to playing poker for a living.  If you're smarter than most of the people in the room, you might be able to make a bit of money, but the overhead - in the case of poker, the money the house charges for the game, in the case of stocks, the exchange fees and broker commissions - means that it's a losing game for the group as a whole, and not very many people can actually make money.  Add to that the computer-based trading - so imagine a poker game where four of the eight players are computer models that are really good (and actively maintained by very smart traders) and you can see where it gets to be very difficult to trade at a profit (versus long term investments, which take advantage of the growth in value in the company). Finally, the risk because of leverage and option trading (which is necessary to really take advantage of inefficiencies) makes it not only hard to make a profit, but easy to lose everything.  Again to the poker analogy, the guys I've known playing poker for a living do it by playing 10-20 games at once - because one game isn't efficient enough, you wouldn't make enough money.  In poker, you can do that fairly safely, especially in limit games; but in the market, if you're leveraging your money you risk losing a lot.  Every action you take to make it "safer" removes some of your profit.