I had wondered what kind of scam it would turn out to be. Investment scam:
“Have you been into investing lately?”
“I would love to share and idea with you about a trading and investment platform on your mail”
“Send me your mail address while I forward you the pdf files so you go through them and see for yourself”
Clearly I need to reply "I spend all my extra money on x” with x being gummi bears or vintage gaming consoles.