What's the price to book of AAPL today (accounting for cash and growth rate of course) since "earnings multiple" matters.
Apple trades at close to five times book value. But if you want to actually account for operating cash flow and growth, using either an operating cash growth model (working capital plus projected cash flows discounted to NPV) or enterprise value calculations (based on terminal growth), it's somewhere closer to $500 per share. That, however, doesn't give the shrewd investor any sensible margin of safety at current market price. The daytrader would never have found anything interesting about Apple when it was an underpriced investment.
Earnings multiples are bs.... only telling you what premium every other fool paid for a security in a sector, not what you should pay.
But let me step back a second: Regarding the earlier point about liquidity and scale. Sure, when you have very large scale positions it becomes more difficult to move the needle as capital needed to do so becomes limited.... But no one here is really in the position of a Warren Buffett, who is currently shopping around for a couple of $20 billion deals. So, in principle, beating the S&P year in and year out is possible, but daytrading would never get you there... but some people will never understand why buying a dollar worth of assets for sixty cents actually increases your return while reducing your risk, versus paying more than a dollar for a dollar of assets which increases your risk but not your return.
Call it what it is... daytrading is basically gambling. But, if you've got money burning a hole in your pocket, at least casinos have martinis and women....