10-year Treasury yields have risen to their highest levels since before the pandemic in recent days. James McDonald, CIO at Hercules Investments, told Insider he expects yields to continue rising. He said they could rise to 2.5% by the end of March and trigger a 20% sell-off in the S&P 500. Yields on 10-year Treasury notes have spiked to a one-year high over the last month, rising above 1.5% as COVID-19 cases fall and vaccinations continue — positive developments for the economic recovery ahead. According to James McDonald, chief investment officer of the alternative asset manager Hercules Investments, the bleeding isn't likely to stop anytime in the coming weeks.