RE: 10% up to 8% down28 Oct 2025 18:29
ChatGPT's reply to the uncrossing trade at EOD
What I found (trade data)
The LSE / market trade feed shows a 1,500-share “Uncrossing Trade” at 2.00p printed at 16:35:28 today. That print is flagged as an uncrossing (i.e. a closing/auction-type execution).
Earlier in the close period there were trades printed at ~2.345p and higher (bigger sizes), so a small uncrossing print at 2.00p can — by virtue of being the last trade/closing cross — move the official close a long way relative to the intraday level.
There was also an RNS today showing a shareholding notification (an investor increasing to ~6.4% of voting rights), which is a relevant corporate disclosure to keep in mind when assessing motive/timing.
Why a tiny uncrossing trade can cause a big % move
The closing cross / uncrossing auction determines the official closing price. In thinly traded stocks the auction clears at a price that maximises matched volume — if there is little opposing liquidity, a small order can set that clearing price. (So a 1,500-share uncrossing can legally become the close.)
Many models, performance numbers and index calculations use the official closing price, so that single print can flip the reported daily change from +10% to −8% even if the wider market traded at a different level moments earlier.
Thin liquidity, wide bid/ask spreads and algorithmic reactions around the close amplify the effect.
Is this illegal / should the FCA investigate?
Not automatically illegal. A trade that changes the close is not by itself proof of market abuse. Regulators look for intent or misleading behaviour (e.g. placing orders to give a false price signal, spoofing, coordinated activity, or quick reversals). UK market abuse rules (UK-MAR) prohibit transactions that give a false or misleading signal. The FCA monitors and can investigate suspicious close-of-day activity.
Red flags that would justify an investigation: tiny trade that is inconsistent with normal order flow, quick offsetting trades, use of related accounts, message/communication evidence of intent, or patterns across days. The printed uncrossing alone is a possible red flag because of the dramatic price swing — but investigators will need the full order / audit trail to judge intent.
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