Mighty timely of them. Question , Is it possible for large companies to keep transactions/sales off the book?

I ask because i found it strange large oil companies were at a stalemate( growth) when oil was skyrocketing. While much smaller companies (that mite not have the furtunate ability to hide assets) were tremendously increasing earnings and profits.

Consider wealthy individuals that hide thier assets in offshore accounts evading taxes. I don't have evidence to back my claim , Its just a gut feeling. It seems fishy.

Any thoughts?