Eu podia colocar no Mural da Amazon...

... mas acho que se aplica a um contexto geral de ações.

Da Carta aos Investidores de 2013:

As I write this, our recent stock performance has been positive, but we constantly remind ourselves of an important point – as I frequently quote famed investor Benjamin Graham in our employee all-hands meetings – “In the short run, the market is a voting machine but in the long run, it is a weighing machine.” We don’t celebrate a 10% increase in the stock price like we celebrate excellent customer experience. We aren’t 10% smarter when that happens and conversely aren’t 10% dumber when the stock goes the other way. We want to be weighed, and we’re always working to build a heavier company.