As Buffett says, the main lesson Graham taught was to approach...

As Buffett says, the main lesson Graham taught was to approach stock investing as an investment in a business. Starts with that and everything else will follow. That and to not lose money.

So that pretty much set the foundation. Everything that follows are just some minor variation in how to assess and understand any given business and investment opportunity.

There's also a belief that Graham is all about "value" - asset, mechanical ratio kind of approach. That Graham's is not about "growth", not like, say, Fisher's approach.

But that, I believe, is a big misunderstanding of Graham's teaching. I mean, as Buffett and Munger have said, growth is part of value. Buying a good business (profitable and growing) at a reasonable price (value). This is what I also took away from Graham's writings.

So while Graham understand and teaches the buying of growth and quality businesses... in his own practise he had more often than not go for the undeniable value of the asset kind. That's probably due to personality and lessons from the Great Depression. But Graham is not beyond going for growth when he clearly sees it - which he apparently did in GEICO, and others that I don't know about.

But of course the further away an investor is from the financials and assets and established history of the business, the greater the speculation weights on the decision. Whether that is wise or risky or profitable depends on the understanding of that business and perhaps some unique insight into the industry and some distant future. Risky for sure, speculative definitely... but returning to the advise that an investor ought to analyse the business, not the stock - all investment are pretty much speculative to some extend.

But that margin of safety, make sure to provide enough cushion of things going wrong... and make sure to only speculate on money we can afford to lose. Graham did advised some 10% I think.