Private prison companies took another dive on Wednesday after Bank of America announced it would no longer finance the facilities.

What's happening: Shares of major private prison companies GEO Group and CoreCivic had another major selloff, slumping 4.2% and 4.4% respectively after the BofA news.

Reuters' Imani Moise, who broke the news, also made waves in March with news that JPMorgan had made a similar declaration, and Wells Fargo also announced it would stop loans to the industry.

Background: Activists have stepped up pressure against the financing of private prisons amid heightened tension over immigration policies from the Trump administration and concerns about facility conditions. Private prisons account for about two-thirds of people held by U.S. Immigration and Customs Enforcement, according to S&P Global Ratings estimates.

Earlier this month, the companies were rocked by an announcement from presidential candidate Sen. Elizabeth Warren, who tweeted about about her plan to terminate private prisons entirely.

That news sent GEO to its biggest intraday drop since March. CoreCivic fell by as much as 6%, the largest intraday decline of the year.

The big picture: GEO Group's stock is up a little more than 3% year-to-date, but has fallen more than 16% since June 18.

CoreCivic's stock is up 14% for the year, but has dropped more than 18% since June 18.

Go deeper: How companies profit from immigrant detention