One of the biggest, and most immediate, effects of Brexit on everyday Americans is how it will change mortgage interest rates.

Greg McBride, chief financial analyst at Bankrate, said rates could sink to record lows in the coming weeks. “If you’re a borrower, don’t wait to lock your rate,” he said, “as this opportunity may not last long.”

They’ve already hit rock bottom this year. In the past month alone, 30-year fixed-rate mortgages have hovered around 3.7 percent, nearly a three-year low. Britain’s vote to leave the European Union is expected to drive rates even lower.

Lawrence Yun, chief economist at the National Association of Realtors, said the low interest rates indicate low confidence in Americans’ ability to handle higher rates, due to a slew of factors both domestic and foreign. Rates have been about 17 percent lower than the median of this decade.

However, McBride said his long-term outlook does not change with the Brexit vote. He still estimates a rebound from ultra-low rates by year’s end.

Mortgage Bankers Association chief economist Michael Fratantoni had forecasted a rate of 4.8 percent by December 2017. That could change with the Brexit referendum passing, however. He noted that Treasury rates had already dropped about 20 basis points by Friday morning.

“At this point, it is unclear whether this will just be a short term disruption, or whether it will have a longer term impact,” Fratantoni said. “Our best guess at this point is that the impact on the mortgage market will be to keep mortgage rates lower for longer, likely leading to another pickup in refinance activity.”

International concerns, particularly slowing growth in China and Brexit, have played a major role in driving down mortgage rates.

International and domestic investors alike drive mortgage interest rates through the mortgage-backed security market. Because these securities are considered relatively stable, they attract buyers when economies and markets elsewhere flounder. Mortgage rates are also heavily influenced by the yield on 10-year Treasury notes, and investors have flocked to them to escape turbulence in foreign markets. Together, they have driven down mortgage rates for Americans.

Early Friday, as global markets shuddered, investors sought safety in gold, driving up the price.

Domestic worries have had a smaller, but notable, effect on keeping rates low. The U.S. economy is healthy, if not surging, with unemployment at its lowest since August 2007 and wage growth nearing pre-recession levels.

Even with the looming fallout from Brexit and slow job growth, Yun at the National Association of Realtors pointed to price and wage upticks when he estimated higher mortgage interest rates. Yun said those increases may kick rates as high as 4.5 percent by this time next year.

Yun said rent is at a seven-year high and gas prices are inching upward. Those increases in prices – markers of inflation – often bump up borrowing rates across the board.

“For those who have been hesitant or busy with other aspects of their life, they should consider refinancing their mortgage to take advantage of the current low rates,” Yun said.

McBride echoed that. He anticipates modest growth to interest rates: “It makes a great time to refinance now regardless of the outlook down the road, simply because of how low rates have fallen.”

The low rates this past quarter have been good for the housing market, though indicative of an overall mediocre economy. Mortgage applications increased 17 percent from the end of March through the beginning of June, according to the Compass Point report using the Mortgage Bankers Association market index. New purchase applications alone saw a boost of 27 percent during this time.

That means that more people are buying homes rather than simply refinancing their mortgages, which is indicative of economic growth.

In any case, McBride recommended investigating refinancing if it’s possible to shave one-half to three-quarters of a percentage point off the interest rate while remaining on a fixed-rate loan.

He added that, because many may also be refinancing their mortgages, to prepare all documents as quickly as possible to ensure your refinancing application is accepted quickly. Typical refinancing costs can range from several hundred to several thousand dollars.