Bayer’s shares slumped as much as 9.2% on Wednesday, wiping out the previous day’s gains, as investors questioned whether a proposed $7.25 billion settlement of cancer lawsuits over its Roundup weedkiller would mark a decisive turnaround.

The German pharmaceuticals and crop protection group said late on Tuesday it had reached an agreement to resolve tens of thousands of current and future product liability claims, after years grappling with legal risks tied to Roundup, acquired in the 2018 takeover of Monsanto.

The stock’s 7.3% surge on Tuesday was more than reversed by an 8% drop as of 1008 GMT.

JPMorgan analysts said the settlement moved in the right direction but noted that Bayer had not disclosed how many plaintiffs must opt in for the deal to proceed, and it was also unclear how willing they might be to accept the offer.

“There remain considerations such as the necessity for court approval and the possibility of a high rate of opt-outs,” they said.

Late on Tuesday, Markus Manns, a portfolio manager at Union Investment, also warned that the proposal was “not yet the breakthrough that many investors had hoped for.”

Both JPMorgan and Manns said much still hinged on an outstanding U.S. Supreme Court ruling on the lawsuits’ overall merits.

Bayer has petitioned the court to invalidate the claims, which are mainly based on state law, arguing that federal regulation in its favor should take precedence.

Stephan Wulf, an analyst at brokerage Oddo BHF, cautioned that a sequence of legal hurdles must be cleared for the settlement to take effect, and that the Supreme Court’s view would be an added uncertainty.

“This is not a done deal yet,” he said.

A Bayer spokesperson said the group would not speculate on its chances of success with the Supreme Court but directed Reuters to a legal brief by U.S. Solicitor General in December, which showed President Donald Trump’s administration agrees with Bayer’s reading of the law at issue.

($1 = 0.8445 euros)

(Reporting by Ludwig Burger, Patricia Weiss in Frankfurt, and Tristan Veyet in Gdansk. Additional reporting by Sanne Schimanski. Editing by Mark Potter)