Shares in Newcastle United rose 15% on Tuesday amid continuing speculation about a possible takeover of the club.
Newcastle struggled on the pitch last season
The club's shares had surged 18% to a four-year high on Monday on suggestions that former chairman Sir John Hall could sell his 28.5% stake in the club.
Newcastle fans have said they would oppose any "Glazer-style" bid for the club from a foreign-based group.
Newcastle's shares closed up 9.5 pence at 69p, boosting the Premier League club's market value to £88.7m.
In a statement on Monday, Sir John Hall - Newcastle's life president - said he had been approached by an unnamed party which could result in the sale of his stake.
Newspaper reports have claimed that two groups- one headed by a local entrepreneur and another based in Malaysia - may be circling the Premiership club.
Fans expressed concerns that the club could be targeted by a foreign businessman similar to US sports tycoon Malcolm Glazer who completed his takeover of Manchester United last month.
"I am in favour of anything that improves the team's chances on the pitch as long as they do not go down the road of Manchester United and sell to a foreign businessman who knows nothing about football," said Ian Gilmour, a member of the Football Supporters' Federation.
In the doldrums
Like the majority of publicly traded football clubs, Newcastle's shares have been in the doldrums in recent years.
The club's shares were valued at 135p when it floated in 1997, but they have been trading at less than 50p.
Newcastle's cause has not been helped by poor performances on the pitch in recent times.
The club finished only 14th in the Premiership last season, failing to automatically qualify for Europe.
Total turnover: £90.2 million
Gate receipts: £33.9m
Analysts said Newcastle was still one of Europe's most valuable football businesses and one of few clubs potentially open to a takeover.
"In terms of its fundamentals, it is a good business," said Harry Philp, a partner at Hermes Sports Partners.
"It has an incredibly loyal supporter base and a fully developed stadium. For Newcastle, it is a question of making the leap from being a well-recognised British brand to being a global brand."
Any successful takeover would need the support of current chairman Freddy Shepherd, who owns about 27% of the club.
Mr Shepherd has been building up his stake in the club in recent months.