[FabHK]

Sure, some derivatives have some utility.

But, ok, Spread Networks spent $300m around 2010 to build a somewhat straighter glass fibre data connection between NY and Chicago. Other companies spent more to build a micro wave connection, since microwaves move faster through air than light through fibre.

Is that money really well spent? And I'm afraid a lot of what happens in finance is similarly private gain, without much social welfare increase.

[pclmulqdq]

That money is very well spent considering that the microwave network technologies developed for trading have huge applications for military and emergency response use. Similarly, millimeter wave technology built for trading firms in New Jersey could rightly be considered as one of the precursors to Starlink.