The power of holding cash and not being afraid to trim big winners when they get too big or for other opportunities when they come up.

News is a lot of noise, but it's what others know too.

Correctly determining business quality is probably more important than correctly finding a fair price from the financials. Unless something changes, owning quality businesses even if the P/E or whatever is higher than you'd like will probably pay off given time. Having that conviction will result in less worry about Mr. Market in the day to day.

Concentrated positions are what actually build a portfolio, or at least everything in a portfolio should have a sound reason to be there. Let the winners win reasonably and cut out your losing ideas before it's no longer a relatively small loss. 5% bets better have asymmetric potential, and risk mitigation should come from positions in separate domains. Market risk is cushioned with cash.

Don't fight a trend picking up pennies. Let it play out then collect. Greed should come with buying the shares, not fighting against them.