Can an executor invest estate money while the estate is being administered in Ontario?

Yes, but with strict constraints. Ontario's Trustee Act imposes a "prudent investor" standard on executors and trustees. An executor must invest estate funds as a prudent investor would — preserving capital, managing risk, and seeking a reasonable return — while keeping in mind that most estate administrations are short-term and the goal is eventual distribution, not long-term growth.

In practice, this usually means keeping liquid funds in interest-bearing accounts, GICs, or similar low-risk, short-term instruments. Speculative investments — individual stocks, cryptocurrency, or risky funds — are generally inappropriate for estate assets during a short administration period, and an executor who loses money on a speculative investment can be held personally liable for the loss.

If the estate contains an existing investment portfolio that the deceased held, the executor must decide promptly whether to retain or liquidate those investments, and document the reasoning. Holding a risky portfolio without review is just as problematic as making a new risky purchase. When in doubt, an executor should consult a financial advisor and an estate lawyer.