Securities house Merrill Lynch delivered the first blow by hoisting a sell sign over the shares. Then some hamfisted trader registered a deal in 300 million shares - more than half LandSec's capital. It was all too much for the high flying shares; they fell 17p to 1,117p.
Merrill takes the view that after their heady run LandSec's shares have moved ahead of the game. "Gearing is very low and the shares are at a high spot premium to forecast net asset value", says analyst Alec Pelmore who is not particularly enthusiastic about another major property group, MEPC, up 4p to 604.5p.
The incorrect share deal remained on trading screens for around 90 minutes before being erased. The mistake occurred at 11.12am when an unidentified agency stockbroker executed a 300 million cross - which would have been worth some pounds 3.1bn. The trade, which should have been 30,000, was not on the Stock Exchange's controversial order book.
Once the rogue trade was removed LandSec's volume was a more realistic 1.7 million.
The rest of the market enjoyed a late surge. Footsie closed 36.1 points higher at a 5,458.5 peak and the supporting indices, to a modest degree, joined the party. At one time Footsie was down 32.9.
So the final week in January has lived up to its bullish reputation. David Schwartz, a stock market historian, has discovered that January has ended with an upward flourish 19 times in the past 22 years.
The excitement among financials continued with Woolwich, on bid and cash distribution hopes, jumping 26.5p to 385p, a peak. Amvescap, the fund manager, rose 34p to 561p. Its has clinched the $500m takeover of a Liechtenstein asset management group. Barclays rose 67p to 1,845p and Halifax enjoyed another rampant display, up 18p to 893p. After its Halifax- inspired gain on Thursday Standard Chartered, the banking group, fell 10p to 365p.
Ladbroke's move for Inter-Continental, the Japanese hotels chain once British owned, lifted the shares 12p to 296p. Bass, also in the running, jumped 50.5p to 970p. The brewing giant has recently sold its betting shop and bingo hall chains and its tenanted pub portfolio. It is the favourite to win the race with a warchest, despite an pounds 850m share buy back, worth more than pounds 2bn.
Railtrack, up 38.5p to 973.5p, remained on the fast track following the discomfort of London & Continental Railways.
Rolls-Royce, a major beneficiary of the order for 1,500 Eurojet engines for 620 Eurofighters, rose 4.5p to 207p. The have been weak on Asian problems and sterling's strength.
BTR fell 2p to 164p following an SBC Warburg placing of 20 million shares at 161p.
Reuters, the information group, tumbled a further 42p (after 62p) to 550p on its legal difficulties in the US. The US development has prompted Dresdner Kleinwort Benson to reduce its recommendation to hold. The investment house says earnings growth could be halved to 4 per cent because "this is incredibly serious for Reuters in the US".
Its Reuters Analytics off-shoot is the subject of a Grand Jury investigation. Allegations have been made that it obtained and used information from a rival system, Bloomberg.
Kode International, the electronic equipment group, provided the day's main takeover action, surging 56p to 143.5p as US venture capitalist, Cornerstone Equity Investors, offered 150p a share.
Memory Corporation, one of the fallen stars of AIM, managed a 1.5p gain to 26.5p after announcing a joint venture with Datrontech for own branded computer memory products. In 1995 Memory touched 547.5p.
Savills, the property agent, added 4.5p to 130.5p. It has sold a 10 per cent interest in stockbroker Killik & Co. to the firm's other partners. It retains a 15 per cent stake. The sale, in effect, recoups the cost of Savills 25 per cent interest.
Gander, a property group, gained 1.75p to 13.75p on bid talks. Bensons Crisps again said it would not recommend a bid of 40p a share and it was not involved in talks. Knox D'Arcy, management consultants with 17 per cent, has said it has made a 40p a share approach.
Phytopharm, developing drugs from plants, added 15p to 80p. It appears to be talking to a number of groups about licensing a number of herbal medicines. including its eczema treatment ZemphyteT. But any agreement is not expected before the company's results are declared in April.