FTSE 100 falls and ex. dividend impacts

FTSE 100 @ 5584.51, -133.88 (-2.34%).
DJIA @ 11855.68, -10.95 (-0.09%)
NASDAQ @ 2306.29, +13.44 (+0.59%)

So the FTSE played catch up with Wall St and Asian markets today with a fall of 2.34% and settling below 5600. As I write the Dow Jones IA is down just 10.94 points or basically treading water.

Took a little time for the following snippet to sink in and it came to me late in the day really.

"Integrated oil companies BP and Royal Dutch Shell both trade in ex-dividend format on Wednesday morning which, all other things being equal, should knock around 17 points from the FTSE 100 value at the outset." (Sharecast).

Basically, the slice of returned capital or dividend for each of these 2 would be equal to a 17 point fall on the FTSE. 
Being just based upon the dividend this would be approx 4.27p off BP and around 25.6p off EACH of the two Royal Dutch Shell listings.
This is entirely due to the weighting and position by capitalisation that each share holds in the FTSE100 which, using yesterdays data (I think) had these 3 companies as follows:


3 - BP ex div by 4.27p (0.95% of 447.75p)
4 - RDS A shares ex div by 25.6p (1.16% of 2216p)
7 - RDS B shares ex div by 25.6p (1.15% of 2221p)


As I said this didn't really register as being of any significance in the context of the markets falls but as I started to trawl around, the following information started to piece a few clues together


5 - Glaxo also went ex div by 16p (1.17% of 1359p)
11 - Astrazeneca went ex div by 51.83p (1.79% of 2896.5p)
9 - BG Group ex div by 6.58p (0.47% of 1413p)
22 - Reckitt Benckiser ex div by 55p (1.62% of 3394p)


Now if BP and Royal Dutch Shell accounted for 17p of the fall by going ex dividend and using a crude calculation (these 3 companies accounted for approx 15% of the FTSE on the 1st April this year).
When I look at the other 4 companies these accounted for a further 11% on the same date, so could feasibly account for another teen digit impact of lets say 13p. 
So, it could be argued that approx 30p, or 0.052%, of the FTSE's fall today is due to ex dividends, which leaves 103.88 points (1.82%) due to market fears.
Only a small consolation but it is a contributory factor that isn't negative.