While it's no secret the housing market has been struggling, it wasn't until this week that we discovered just how dire the situation has become.

On Tuesday, the National Association of Realtors reported that existing home sales, which account for roughly 90% of the American housing market, fell in March for the seventh time in eight months. At a seasonally adjusted annual rate of 4.59 million sales, they were 0.2% below February and a disturbing 7.5% under the same month last year.

"There really should be stronger levels of home sales given our population growth," said NAR's chief economist Lawrence Yun. "In contrast, price growth is rising faster than historical norms because of inventory shortages."

To add insult to injury, the U.S. Census Bureau announced on Wednesday that new homes sales are in freefall as well. Sales of new single-family houses in March were at a seasonally adjusted annual rate of 384,000. This was 14.5% below the February rate and 13.3% less than the March 2013 estimate of 443,000.

As The Wall Street Journal pointed out, last month's figure was the lowest annual pace since July of 2013 and was far below economists' expectations. The consensus forecast called for a seasonally adjusted annual rate of 450,000.

Just to be clear, it's not surprising that both new and existing home sales were down in March, as we've gotten numerous indications of lackluster activity over the last few months. Among others, data from the Mortgage Bankers Association shows that mortgage application volumes fell out of bed after interest rates began rising last year, and mortgage originations recently plunged by 66% at the nation's four largest banks compared to the year-ago period.

What is shocking, however, is just how steep the decline in homes sales has turned out to be. This is particularly the case when you consider that we're on the cusp of the prime selling season -- that is, when these figures should be heading up.

Is this something to be concerned about? If you own stock in banks or homebuilders, then the answer to this is clearly yes. If not, it probably won't make a huge difference unless you're thinking about getting into the housing market yourself this summer. But either way, these are critical trends that every investor and analyst needs to keep their eyes on.