S&P Global Ratings put its BB issuer credit rating on Six Flags Entertainment Corp. /zigman2/quotes/208050417/composite SIX +3.31% on review for a possible downgrade on Friday, after the company slashed its 2020 adjusted EBITDA guidance amid a slump in revenue and higher wage and investment costs. The ratings agency placed the rating on CreditWatch negative and said it will resolve the action as soon as it has assessed the company's investments in its core business and evaluated whether they can halt EBITDA margin erosion. "We will also consider the impact of increased EBITDA volatility on business risks, and whether to tighten the 4x downgrade threshold at the current 'BB' rating," S&P said in a statement. "We will also address the possibility of future revenue and cost variability in our base-case forecast, the effect of the dividend reduction to preserve liquidity on credit measures, and management's policy commitment to its 3x-4x leverage range." Six Flags stock tumbled on Thursday, after the company swung to a surprise loss in the fourth quarter, offered downbeat guidance and cut its dividend. The company said weak attendance numbers, falling admissions spending and higher wage costs were weighing on performance. The stock was up 3.3% Friday. Spreads on the company's most active bonds, the 4.875% notes that mature in July of 2024, widened 76 basis points on Thursday to 242 basis points over comparable Treasurys, according to MarketAxess.