A comment on this graph that I found on lavoce.info. It is the Mediaset S.p.a. quotation on December 14th.
And here the relevant timing of the confidence in the Italian Parliament:
10.00 - Expected: Majority 311, Opposition 310.
Dont'-know: Scilipoti, Calearo, Guzzanti, Siliquini.
Still absent: Bongiorno, Cosenza.
[Mediaset slightly going down: uncertainty]
12.13 - Expected: Majority 311, Opposition 313.
Bongiorno, Cosenza, Guzzanti claim they will vote NO.
[Madiaset goes down]
12.57 - Actual: Majority 312, Opposition 311.
Surprisingly Polidori votes YES.
There's a kind of fighting in the Parliament.
[Mediaset starts going up]
13.41 - Actual: Majority 314, Opposition 311.
Scilipoti and Calearo eventually decide and vote YES.
The final result is declared at 13.43: Berlusconi got the confidence.
[Mediaset reaches the maximum]