At their close last night of 228p, the shares had tripled since Tuesday morning, on the news that MAID had signed a strategic alliance with Microsoft, the world's largest software developer. Mr Wagner, who holds 24.5 million shares bought for the equivalent of "a few hundred pounds", now has a pounds 56m stake in the company.
Sounding highly pleased, he said last night he had "no intention of selling".
Mr Wagner's company has seen its fortunes ebb and flow in recent years. In the late 1980s, long before MAID was taken public, Mr Wagner was forced to refinance his 1979 Aston Martin V8 Saloon to provide working capital. (He has since bought a second Aston Martin, a DB6.) The flotation itself was a difficult affair: having pitched the shares at 150p, the company's advisers were forced to accept a price of 110p to get the issue away. Even then, it was not until this week, on the strength of the Microsoft alliance, that the shares first traded above their issue price.
Indeed, the stock plunged to as low as 43p in mid-1994, as investors seemed unimpressed with Mr Wagner's plans to be a pre-eminent global supplier of financial information. "I am pleased our institutional shareholders have stuck with us," Mr Wagner said last night. "We have spent the last year in penitentary."
The shares doubled on Tuesday to 168p, and then rose a further 60p yesterday. Mr Wagner said he thought investors on the West Coast of the US were responsible for the second wave of buying. "They were just waking up to the news out there."
Mr Wagner has also made a believer of his father, formerly a BMW car dealer in London, who owns a further 9 million shares in MAID, bought for about pounds 17,000 several years ago. His stake was worth just over pounds 20m last night.
"My father rang me yesterday and asked if this was all a dream," Mr Wagner said.
The link with Microsoft gives MAID a distribution channel for its financial information services to a potential audience of 9 million within the next 12 months. The UK company is one of several hundred to offer services on the Microsoft Network, a gateway to the Internet computer network and a general information service that will be pre-loaded with Windows 95, Microsoft's new generation operating system.
Mr Wagner said this week the link had been agreed for some time. When the US Department of Justice said on Monday it would not force Microsoft to "unbundle" the network and operating system, Mr Wagner decided to announce the alliance.