Using ancient Egyptian construction method could cause investors to lose money (7,6)
I believe the answer is:
pyramid scheme
'method could cause investors to lose money' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'using ancient egyptian construction' is the wordplay.
I cannot really understand how this works, but
'construction' could be 'pyramid' (pyramid is a kind of construction) and 'pyramid' is present in the answer.
The remaining letters 'scheme' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for pyramid scheme that I've seen before include "Sort of financial scam for which Bernie Madoff got a prison sentence of 150 years in 2009" , "Money-making ramp" .)