Wine auctions and market manipulation

[JacobH]

it seems that not acting, not bidding, cannot of itself be manipulative.

No longer my area, but I am surprised that market manipulation can only be achieved by an act rather than an omission so that a failure to bid could not be prohibited. It seems to me the question is really why there was a failure to bid: was it to secure a dominant market position and, if that were the intention, was the failure likely to have the effect of fixing prices or creating other unfair trading conditions?

2. The following behaviour shall, inter alia, be considered as market manipulation:
a. the conduct by a person, or persons acting in collaboration, to secure a dominant position over the supply of or demand for a financial instrument, related spot commodity contracts or auctioned products based on emission allowances which has, or is likely to have, the effect of fixing, directly or indirectly, purchase or sale prices or creates, or is likely to create, other unfair trading conditions;

EU MAR, Article 12.

[Clearly you should not rely on this back-of-the-envelope legal analysis for any purpose whatsoever.]

[Glenn E.]

it seems that not acting, not bidding, cannot of itself be manipulative.

No longer my area, but I am surprised that market manipulation can only be achieved by an act rather than an omission so that a failure to bid could not be prohibited. It seems to me the question is really why there was a failure to bid: was it to secure a dominant market position and, if that were the intention, was the failure likely to have the effect of fixing prices or creating other unfair trading conditions?

I was thinking pretty much along these lines. Not only that, but was the "failure to act" made public ahead of time?

Think of Elon Musk's power with crypto. Some of those coins rise and fall every time he simply mentions them. Can you imagine what would happen if he tweeted something along the lines of "there's no way I'm buying bitcoin right now."

That's a very different thing that simply not buying it. Stating that he's not going to buy could very easily be, and be seen as, an attempt to manipulate the market.

[Doggett]

Broadcasting that you will not be bidding would surely be ‘an act’, where as privately discussing would not necessarily be so. If jdaw tweeted he would not be bidding so as not to inflate the price for a friend (and any interested or potentially involved party actually read it), then that would be more of an act that could influence the bidding, through information that was stated prior to the auction, and a provable one, rather than a private agreement that would not have the same potential influence.