A number of S&P/ASX 200 Index (ASX: XJO) shares could come under pressure on Wednesday.
A group of 12 ASX-listed companies are trading ex-dividend today, which means their share prices will no longer include the value of their latest payout.
That alone is expected to have a decent impact on the broader market.
According to The Australian, the combined ex-dividend moves could shave around 31 points from the ASX 200.
With futures already pointing lower, that could make market open look a little heavier than usual.
Here's the shares investors will want to keep an eye on.

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The ex-dividend moves to watch today
There are a few larger payouts sitting near the top of today's list.
Sonic Healthcare Ltd (ASX: SHL) closed Tuesday at $19.64 and is trading ex-dividend for 63 cents per share. The payment is 60% franked and is due on 17 September.
Monadelphous Group Ltd (ASX: MND) is not far behind. Its shares closed at $28.78 before going ex-dividend for a 59-cent fully-franked payout.
Origin Energy Ltd (ASX: ORG) and Seek Ltd (ASX: SEK) also have decent-sized dividends dropping off today.
Origin's 30-cent fully-franked dividend comes off an $11.70 closing share price, while Seek's 25-cent fully-franked payment comes off a $14.32 close.
Furthermore, Newmont Corporation (ASX: NEM) closed at $176.04 and is trading without its 25.95-cent unfranked dividend.
More ASX shares joining the list
There are also several smaller payouts coming off the board as well.
Downer EDI Ltd (ASX: DOW) closed Tuesday at $6.55 and is trading ex-dividend for 16.3 cents per share. Steadfast Group Ltd (ASX: SDF) closed at $5.84 and is going ex-dividend for 12.75 cents.
Medibank Private Ltd (ASX: MPL) is also on the list. The shares closed at $4.81 on Tuesday, with a 10.9-cent dividend going ex today.
Among the miners, Yancoal Australia Ltd (ASX: YAL) is trading ex-dividend for 7 cents per share, and Whitehaven Coal Ltd (ASX: WHC) is doing the same for 6 cents.
PLS Group Ltd (ASX: PLS) is trading ex-dividend for 5 cents, with Karoon Energy Ltd (ASX: KAR) rounding out the group with a 1.2-cent payout.
All of the 7 dividends are fully franked.
Why today's moves could be misleading
Keep in mind, trading ex-dividend does not automatically mean a stock will fall on the day. There's still plenty happening in the broader market that can push shares either way.
Nonetheless, the ASX 200 futures are expected to open at a fall of around 0.9%.