So, according to the old City adage, traders should sell in May and then go away for their summer breaks. Late last month they started to drift back into the market hunting for bargains. Over the past two days, however, they have returned with a vengeance. Now it is not the fundamentals of the economy that are driving prices higher. Guessing the target of the next big bid is the name of the game.
After last month's audacious $39bn swoop on Potash Corp by BHP Billiton anything is possible, traders argue. No hoary old rumour is going unspread. Discovering themselves in the yesterday were a host of blue chip firms from travel agent Tui Travel to phone provider Cable & Wireless Communications.
There was, however, only news of one actual possible deal. Having been fending off the attentions of Cinven since the private equity firm made an approach in May, water meter group Spice said yesterday that another - unnamed - bidder has entered the fray. Although it stressed a deal may not materialise, shares in Spice closed up 6.75p - or 12% - at 63.25p valuing the firm at £223m.
News that the Chinese economy remains strong, according to the latest purchasing managers data, helped boost mining stocks early in the trading day. Kazakhmys closed up 80p at £12.36 with Xstrata up 62.5p at £10.88.5. Shares in Rio Tinto closed up 201p at £35.01 with Antofagasta up 62p at £10.94 and Anglo American up 116.5p at £24.56.5.
Further support was given to the FTSE 100 index later in the day by stronger-than-expected US manufacturing data which broke with the downbeat trend of recent US data. On Wall Street the DJIA was pushed more than 200 points higher, helping the FTSE 100 index to close up 141.19 points at 5,366.41.
Results from workwear rental company Johnson Services Group showing a 17% increase in half year profits, helped its shares gain 21% to 17.5p. 'Apps' creator 2ergo, meanwhile, saw its shares leap almost 10% to 59.5p after an upbeat trading update.
Land Securities added 29.5p to 641p after JP Morgan Cazenove named the property company as its top large cap pick as it moved its recommendation to overweight from neutral.
Lastly, traders are watching Aqua Bounty Technologies with keen interest. The company has developed a genetically engineered salmon, which grows twice as fast as traditional salmon. Heath officials in the US are due to debate whether it should be approved on September 19 and hopes among some traders are high. Even though the shares remained unchanged at 10.5p, it seems fitting that on a day filled with so many fishy tales, one bit of speculation should actually be about fish.