The firm, which lost its "AAA" financial strength rating at Fitch Ratings on Friday, gained over 30% to $7.97.
The rise came despite Ambac losing its "AAA" financial strength rating at Fitch Ratings on Friday, and both firms being on watch for downgrade at Standard & Poor's and Moody's Investor Services.
Fitch Ratings cut FGIC's financial strength rating Wednesday to double-A from triple-A, and it did the same to Ambac earlier this month.
Chief rival, Ambac Financial Group, which has already seen its financial strength rating dropped to AA by Fitch Ratings, gained 79 cents, or 7.3%, to $11.64.
Ambac, which has already seen its crucial AAA financial strength rating cut to AA by Fitch Ratings, gained $1.94, or 16.7%, to $13.58 Friday, while MBIA added 40 cents, or 2.6%, to $15.90.
MBIA will be a stock to watch, after Fitch Ratings slashed its AAA insurer financial strength rating to AA on Friday.
The AAA financial strength rating is crucial to bond insurers because they effectively transfer their ratings to bond issuers.
Bond insurers strive to maintain a triple-A financial strength rating because their business is effectively transferring that rating to lower-rated bond issuers, who use the higher rating to get better pricing in the bond market.
Bond insurers like Ambac and rival MBIA need to maintain sufficient capital levels in order to retain key AAA financial strength rating, and though investors snubbed Ambac's plan, two of the major ratings agencies said its success could help.
The AAA financial strength rating is so important to bond insurers because they're effectively transferring their ratings to bond issuers.
