It all started with swirling stories that a bid for National Westminster Bank was about to materialise. Then the futures market soared, propelling the cash market higher.
Suddenly there were whispers the boys in dark glasses in the futures pit had got a whiff of at least some of the contents of Gordon Brown's Budget. And, ran the yarn, the market had little to fear, with much of the pain due to be inflicted on the consumer.
Hopes that US interest rates would remain unchanged and a firm Government stocks market were other favourable influences.
With many market makers having decided to remain short of stock ahead of the Budget the sudden futures-led activity caught them on the hop. Their scramble for cover sent Footsie rocketing, with pounds 24.4bn added to company values. The index gained a staggering 123.7 points to 4,728.3; it was the biggest jump since the turmoil of the 1987 crash although in percentage terms it lagged behind the ERM upsurge in 1992.
The index is now 54.8 below its closing peak, hit last month.
Turnover was modest, underlining the technical nature of the upsurge. And the supporting indices were left limping lamely behind. The FTSE 250 index gained a mundane 21.2 points and the FTSE SmallCap managed to record a miserable 0.4 gain.
Many market men were bemused by the Footsie charge. "It's bloody crazy; the market has lost touch with reality," said one.
The NatWest story at one time had the bank leading the Footsie leader board. The shares were up 47p; they closed 42p higher at 849.5p in relatively busy trading. Commerzbank, the German group, was put forward as the new favourite to strike, although its bid candidature was dismissed by most observers.
The NatWest display inspired other financials and with money shares now such a powerful Footsie influence the index was already on a roll when the futures activity exploded. At the end of trading the September futures were showing a hefty premium to the cash index.
Lloyds TSB was top of the blue-chip pile with a 39.5p gain to 655.5p. Bank of Scotland, up 22p to 406p, and HSBC, 86p to 1,934.5p, were among the others in the money.
Utilities were strong on the unexpectedly benign approach of Margaret Beckett, President of the Board of Trade, and stories that Mr Brown's windfall tax would not be too onerous. ScottishPower glowed 22p to 413p and Thames Water flowed 34.5p to 728p.
BSkyB led the motley collection of out-of-favour blue chips with an 11p fall to 429p. LucasVarity, undertaking a 1.5 million share buyback at 205p, was another to miss the fun, off 3.5p to 204.5p. Hillsdown Holdings, the food and furniture group, fell 5p to 164p. It is meeting analysts and ABN Amro Hoare Govett quickly cut its profits forecast by pounds 10m to pounds 160m.
Perkins Foods held at 82.5p after Henderson Crosthwaite said buy. Iceland, the frozen food chain, hardened 5.5p to 87p; NatWest Securities lifted this year's profit forecast by pounds 5m to pounds 54m and next by pounds 11m to pounds 60m.
British Borneo Petroleum Syndicate rose 27.5p to 1,445p, with HSBC said to be making positive noises.
Amersham International's Norwegian merger prompted an 87.5p gain to 1,682.5p. It encouraged thoughts of more industry deals, with Biocompatibles International moving 46p ahead to 1,347.5p.
Results left MFI Furniture off 6p at 129p; IOC International, an optics electronic company, suffered the day's biggest fall, nearly halving to 67.5p after warning of a possible loss this year. In March the shares were 178.5p.
English National Investment Co, off 5p to 259p, confirmed it had taken a 29.9 per cent interest in Italian football club Vicenza. Bahamas-based multi-millionaire Joseph Lewis, who has 25 per cent of Glasgow Rangers, controls ENIC.
Thomas Potts returned from suspension after its failure to take over Coalite, 4.5p lower at 7.5p and Consolidated Coal was cut 5p to 7.5p following disclosures of more mining problems and plans to make a pounds 1.8m rights issue.
Regent Inns was 0.5p lower at 284.5p. The shares rallied 22p after the company said it knew of no reason for the recent share weakness. Earlier this month they were above 300p.
EFT jumped 38p to 172.5p on the Bank of Scotland bid.
Shares of Acorn, the computer group, are weak, falling 14p to 173.5p yesterday in active trading. There are suggestions Olivetti, the Italian group, is planning to sell more shares through the Lehman Brothers investment house. The Italians, who have been selling assets to cut debts, once controlled Acorn. They have gradually reduced their involvement and earlier this year Lehman sold shares to 20 institutions at around 190p. In its last year Acorn cut losses from pounds 12.6m to pounds 6.3m. Its shares topped 300p last year.
Bridport-Gundry, once famed for its fishing nets, is continuing to sell its traditional operations to concentrate on aviation products. It is selling a twine maker and a fishing net operation for around pounds 1.7m. The shares rose 17p to 116.5p.