Sand is actually used to make Silicon Chips which are used in electronics, and Solar Cells to generate power. In other words, sand requires some refinement in order to be useful.
Alphabet and Meta are the holding companies for Google and Facebook respectively.
The term brought up by Jack, "Irrational Exuberance", originated with the Former Federal Reserve Bank Chairman Alan Greenspan. It is essentially a variation of another phrase he brought up, "Don't believe the hype".