My boring answer: none directly, though an index fund I invest in has a small share of Apple, Microsoft, Google, Amazon and Facebook. I already work in tech, both at my main and side jobs, so not being too invested in tech seems wise even if I don't see it blowing up again.
I've felt the same way over the years, though my belief in that maxim is fading for at least two reasons. One, is that if you're going to extend beyond index funds, it's probably best to invest in companies/industries you know best. And secondly, "tech" is a very broad industry, and there's no reason to think it couldn't come to be a larger and larger share of the whole economy. "Tech" is set to continue disrupting industrial, transportation, agricultural, and energy sectors. I think when you look at it that way, it's almost foolish to avoid tech. Oh, and I'll add a third: would you rather invest in something that is growing, or something that is stagnant/dying?
He is making a generalization. Apple makes about 80% of the market's profits with their phones. They sell a ton and bank on it. The other companies either don't sell a lot, or like Samsung, they sell a ton but barely make a profit.
Depends on the quarter. Last year there was a quarter where Apple ended up with over 100% profit share because, in aggregate, everyone else lost money. http://fortune.com/2016/11/04/apple-smartphone-profits/
Agree, I'm ok listing companies I own (see above), but how many shares and how much value is nobody's business.
It might not be anyones business, but it also shows the faith or future you see in the company. Higher the amount of shares then the more you see their upside. The lower the number, the more they have downside. Not asking to see how many shares OP owns, but can see it's relevance.
The amount of shares and value is all relative and has no bearing on "the faith or future you see in the company". Somebody investing $1,000 in Apple who only has $1,000 to invest is the same as somebody investing 10M who has 10M to invest.
I believe the real question you're looking for, is what percent of your portfolio is each of your companies.
Tesla. It is clear that world is going towards renewables. It is also clear that electric vehicle is here to stay. Even if there is an alternative out there that meets the renewable energy needs, it will take more than a decade for it to fully commercialize so Tesla has its place. I think that the giga factories and solar city can be huge businesses. Tesla's truck with its auto-pilot (even if it is good enough to drive on freeways) can be a huge cost saver for transportation companies.