Paint the technology sector with the same brush at your own peril, warns a finance professor.
"Older technology companies are behaving very different from the younger technology companies," said Aswath Damodaran, professor of finance at the Stern School of Business at New York University
He breaks down tech companies by founding age, dividing them into categories such as young, teenage, aging and old tech. His own portfolio shows a mix of tech companies across age groups. He owns both Apple and Microsoft, companies he'd categorize as "aging tech." And until recently he had Twitter (young tech) and Oracle (very old tech) too.
"At the right price I'll buy any company," Damodaran said.