The market rally is also helping retirement portfolios, so that “a 55-year-old investor, for example, may now be on track for about 18 percent more retirement income than they were a few months ago,” the company said in a statement.

According to BlackRock’s CoRI Retirement Indexes, which are designed to help investors estimate how much annual retirement income their current savings can generate starting at age 65, recent changes indicate a substantial drop in cost for future income.

Since early November, the company said, the CoRI Index and the S&P 500 have generally been moving in opposite directions, which has allowed investors to see higher returns from the S&P 500, and as a result greater income “buying power” in their savings, even as the cost of that income is “getting significantly cheaper.”

While the news is good at present, BlackRock also pointed out that the December rate hike emphasizes how important it is for investors to keep a close eye on how much they need to save so that when retirement comes, they’ll have the level of income they want. “This will be particularly critical in the coming months,” the company concluded, “as we continue to see how the markets settle into this higher interest rate environment.”