There are 7 US tech companies founded after 1970 worth over $100 billion. Can you name them all?

Sam Altman, president of Y Combinator, just tweeted out a bunch of interesting factoids about some of the biggest US tech companies.

There are seven US tech companies founded after 1970 worth over $100 billion, he discovered.

Before we name them, can you guess?

Here are some hints.

Their current market caps are:

• $703 billion
• $443 billion
• $368 billion
• $269 billion
• $247 billion
• $246 billion
• $171 billion
• $144 billion.

Altman gathered up the ages of their founders too:

 

But, he notes, this is "younger than the average age of NASA engineers when we landed on the moon (28)."

These are the years they were founded (listed in order of market cap) 

1976, 1998, 1975, 2004, 1994, 1977, 1984

One more hint:

These are the first letters of the company's names:

A, G, M, F, A, O, C

 

Did you guess? 

Apple, Google, Microsoft, Facebook, Amazon, Oracle, Cisco