His essay, A Diamond in the North, focused on the diamond market in the NWT and wise investing in the stock market.
"Money, I love it! The only problem is that I never seem to have enough of it," his essay began.
His words paid off. He now has a $750 cheque to fatten his bank account.
Grundy said he was always interested in the topic of investing.
"It's quite an interesting challenge to see investments grow," he said.
Charles Dent, MLA and Minister of Justice, said he was pleased to see Grundy win.
"It's a new way of representing the territories," Dent said.
Tony Wong, registrar for the NWT Securities and Corporate Registrics, sponsor of the contest, said the essay had Northern appeal and relevance.
"He has a good grasp of investing. His essay was well-researched," Wong said.