There is academic research that shows 80% of the benefit of diversification can be achieved with holding just 15 stocks .

There is no point holding much more stocks because the more stocks you hold , the more market-like your performance will be.

What are the trading rules you have posted on your computer?


> Be patient—wait for the opportunity.
>» Trade on your own ideas and style.
*> Never trade impulsively, especially on other people's advice.
*• Don't risk too much on one event or company.
> Stay focused, especially when the markets are moving.
*• Anticipate, don't react.
>• Listen to the market, not outside opinions.
*• Think trades through, including profit/loss exit points, before you
put them on.
> If you are unsure about a position, just get out.
»» Force yourself to trade against the consensus.
*• Trade pattern recognition.
> Look past tomorrow; develop a six-month and one-year outlook.
> Prices move before fundamentals.
*• It is a warning flag if the market is not responding to data correctly.
* Be totally flexible; be able to admit when you are wrong.
*• You will be wrong often; recognize winners and losers fast.
^ Start each day from last night's close, not your original cost.
> Adding to losers is easy but usually wrong.
>• Force yourself to buy on extreme weakness and sell on extreme
strength.
*• Get rid of all distractions.
^ Remain confident — the opportunities never stop.

I guess the implication is that holding on to a losing stock can be
a mistake, even if it bounces back, if the money could have been
utilized more effectively elsewhere.

Answer
Absolutely. By cleaning out my portfolio and reinvesting in solid
stocks, I made back much more money than I would have if I had
kept the other stocks and waited for a dead cat bounce

Quotes

Question:
So you are at least able to bite the bullet and admit that you
made a mistake by getting out, and then get back in at a higher
price. You don't say, "I can't get buy it now; I sold it $10 lower."

Answer:
I may have done that in earlier years, but now buying back a stock at
a higher price doesn't bother me at all. To me, the successful stock is
not one that I bought at 10 and held to a 100, but one where I picked
up 7 points here, 5 here, another 8 here, and caught a major part of
the move

Stuart Walton will be holding a stock for about a week . But he will be in and out the stock twice in the same day and 6 times in the week.

Sampling Method

A new way to invest in the stock market is to do sampling and statistical inference.
1. You take 100 person who owned a particular stock and track their actions (either buying or selling) and their reasons behind their action.
2. Then with the data collected , you infer the sentiments of the whole market.

This method is created from the idea that most people think alike and you can predict the markets from studying a group of independent individuals.

It's a country club environment where success has more to do with politics than with your performance

A firm or stock that has unusually high price rise also indicate that it is an risky investment . Because risk is measured in standard deviation , that is , the quantity that move in either direction (up or down ) from the mean or average

The goal is to make money and keep your risk under control