[nailer]

> High-frequency trading replaced a whole profession in the financial sectors.

But it also created one. Someone has to both conceive and write each algo. This looks like the old profession, except with different people because Excel is being replaced by C++.

[PakG1]

Poor logic. The algos get shared and replicated, especially given open source. For example:

http://www.vanityfair.com/business/2013/09/michael-lewis-gol...

The algos can be created by fewer people. Traders are being replaced by the algos, and fewer people are required to create the algos than do the original trading. So your point does not have a 1-to-1 job creation-destruction ratio.