Ocado shares fell more than 7% on Friday in the absence of any bid developments after soaring the day before on a Times newspaper report of possible takeover interest in the online supermarket and technology group.
The Times reported talk of bid interest from more than one US suitor including Amazon, pondering the merits of an offer worth 800 pence ($10.21) per share, an 86% premium to Ocado's Wednesday closing price of 430 pence.
Ocado and Amazon both declined to comment.
Having risen as much as 47% on Thursday and closing up 32%, Ocado shares were down 7.5% by 0956 GMT on Friday.
Given Thursday's move in Ocado's share price, under UK takeover rules if the group had received an approach that could result in a firm offer it would normally be obliged to notify the market.
If a suitor was planning to make an approach but hadn't yet done so, and if Ocado was unaware and details had leaked, the obligation to consult the Takeover Panel would sit with the possible bidder. It might be required to make a statement.
Analysts said that the lack of any statements told its own story, indicating the bid speculation could be wide of the mark.
Shore Capital analyst Clive Black said he would be amazed if the Takeover Panel had not contacted both Ocado and Amazon to seek clarification as to the veracity of the Times report.
"That there was no announcement from either party on the 22 June or on the morning of the 23rd suggests to us that there was nothing to report, and as such other factors must be at play," he said.
He said investors short of Ocado prior to Thursday may have moved quickly in order to avoid being the wrong side of the bid talk, fuelling the stock's mark-up.
Baillie Gifford, Ocado's second largest shareholder with a 12% stake, said the group should remain independent.
"It would be a dreadful shame if the UK were to lose one of its leading listed technology companies when there is so much potential remaining," said Tom Slater of Baillie Gifford, which manages the Scottish Mortgage Investment Trust.
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