Opportunity zone funds, particularly those focused on obtaining capital from third parties, have raised about $4.5B, according to the most recent survey of funds by Novogradac & Co., a San Francisco-based national accountancy and consulting firm.

That total is up about 40% from about two months ago, the last time Novogradac tallied investment in opportunity zone funds. The company published the latest survey, the Novogradac Opportunity Funds Listing, on Tuesday. The rise is ahead of the Dec. 31 deadline to obtain the most tax reduction possible from OZs under the current rules.

“Barring legislation that extends the deadline for investment, the end of 2019 is a crucial date for some investors,” Novogradac Managing Partner Michael Novogradac said in a statement.

The Novogradac Opportunity Funds Listing total is less than the entire universe of OZ funds, because not all of the funds offered information on their investments. Of the 366 OZs the company tracks, only 184 have reported their investment totals.

Also, other OZ funds don't seek investment from third-party investors, but rather are formed among private investors. Those aren't tracked by the accountancy.

Even so, the $4.5B total so far seems to reflect persistent hesitancy among investors to put capital into the funds, despite previous optimistic forecasts. Late last year, U.S. Treasury Secretary Steven Mnuchin, whose department oversees the program, predicted opportunity zones would attract $100B in investment, though he didn't specify a timetable.

The final regulations governing the funds aren't quite complete either. Last week, the IRS and the Treasury Department submitted their final set of regulations to the Office of Management and Budget, which will release them to the public once it has reviewed the regulations.

Opportunity zones are under political fire these days, and various bills have been introduced lately in both the Senate and House of Representatives to modify the program, especially by tightening reporting standards. In large part, these measures are in response to reports of irregularities in the formation of opportunity zones and the notion that well-to-do areas are benefiting too much from the program.

Among the $4.5B in investment reported by the Novogradac Opportunity Funds List, almost three-quarters (74%) of the funds had some residential real estate component, and 12.3% were focused entirely on residential properties. Hospitality properties were a component for 22.8% of the funds raised, the report says.

Of the 184 funds tracked by Novogradac that provided data on their size, the average was more than $24M raised. A dozen funds were much larger, reporting more than $100M raised. Almost half of the funds (45%) are investing nationally, while 20% report they are focused on a single metro area.