Up to 70% of the share trading in Dutch blue-chip stocks is carried out by computer, without human intervention, the Financieele Dagblad reports on Monday.

Two years ago, traders estimated between 30% and 50% of shares were traded by computer.
The increase is due to the rise of automated trading systems and the growth in complex algorithmic trading – using mathmatical formulas to trade at very high speeds – the paper says.
‘Some 20% of Dutch blue-chip share trades are the result of high-speed trading,’ Cees vermaas, head of European trading at the NTSE Euronext stock exchange, is quoted as saying.
Optiver, IMC and All Options are among the big automated trading houses in the Netherlands, the paper says.
High-speed trading has been criticised for disadvantaging long-term and private investors.