Fairly tempted to put in an order for some AAPL now...
If AAPL were underpriced, there would be enormous buy pressure to the point that it is no longer underpriced.
(Sidenote: Among one of the loudest proponents of the conspiracy theory is John Gruber, who today proclaimed that $500 proved it. Only the article he linked actually said $550. It turns out that there are psychological pivot points that are often hit nearing close. The market is made by people, and people understand and gravitate to emotional numbers)
But suppose the founders of Airbnb came to you when they were raising angel money. I'm sure they were convinced at that time (maybe objectively irrationally) that investing in their company was a "surefire deal." They were passed on by Fred Wilson (the equivalent of your "rich person with hundreds of staff"), among countless others I'm sure.
By this point, their returns are certainly far more than 12-15%.
There are lots of ideas, but the tried and true one is 'Ponzi Scheme' :-)
I'm not an experienced trader, but I know about the efficient-markets hypothesis and that analyses such as this one are often "priced-in" to a certain extent. But when the market opens on Tuesday, AAPL is going to go up or down. "Underpriced" is a measure that can only be fully assessed in retrospect -- if AAPL goes up on Tuesday, it was underpriced tonight.
You're right that there are tens of thousands of large players with billions, all trying to screw each other over. I believe that 100%. But there's still room in there for Joe Normal to buy some AAPL stock. If his hunch is correct, the stock will go up in value and he'll make money. Individual people still make money trading stocks, and it's "naive" to think it's solely based on luck.
The market is speculative. A lot of people are speculating that Apple's best days are past them -- which is how $9 billion worth of AAPL was sold in the $500 range on Friday -- while a lot of people are speculating that it is still a growth company. Those competing interests set the market price (and FWIW those who bought at $700 -- if they actually still believed in that entrance price, would be doubling down right now for dollar-cost averaging, which itself would pull the price up).
What I said above is not at all what the conspiracy theory is, which is where everyone apparently thinks everything is fantastic and it's going to shoot to the moon and there is no uncertainty or risk, but for options reasons everyone is looking the other way for a couple of weeks/months and letting it slide because something-something-options.
Market manipulation absolutely happens, and it happens a lot. However it generally targets low volume, low cap, low interest equities, or less common instruments like resource futures. It would be incredibly expensive to manipulate AAPL, it being one of the most watched, most traded equities.
Of course many people will disagree but hindsight is always going to be 20/20, and many people like to pretend that they know something.
But then again - there aren't any tests to pass before one can trade - so trade away.
But remember - you both look like dancing pigeons to professional traders (http://rationalwiki.org/wiki/Skinner_box).
Professional traders like this cat?
http://www.npr.org/blogs/money/2013/01/14/169326326/housecat...
It's not hard to make money in the market. It's not hard to see real, after-tax, inflation adjusted gains. Carefully picking companies in a buy-and-hold strategy is a reliable place to park your money for 3-8% growth.
These guys aren't pretending to be day-traders. Looking at fund performance, as I'm sure you know, very very few managed funds beat the market with any consistency. There's too much hand-wavy "the big banks and funds play the little guy as a pawn" paranoia. Yes, you can make yourself a pawn by trying to play Gordon Gecko with your E-Trade account. But cost-averaging into a stock that you chose and believe in is both effective and open to everybody.
And who knows. There are well told stories of amateur investors making literally billions of dollars finding holes in option contracts that the hedge funds and IBanks missed.
They started with $100k pooled together from 3 guys' life savings. How much did they make?
Exactly.
The wikipedia article, short as it is, covers through 2010 when that $100k grew to "100 to 300 Million." Read the latest write-up of them in FT. It's a billion dollar venture now.