The article's paywalled so I don't know if already mentions it, but the attack took place on the 50th anniversary of the Yom Kippur war and also coincided with

The article's paywalled so I don't know if already mentions it, but the attack took place on the 50th anniversary of the Yom Kippur war and also coincided with Simchat Torah. Hamas and other militant groups have previously used days of historical and religious significance to launch a wave of attacks (usually rockets), so there's a strong chance that some random trader just made an educated guess that an incident would happen on that day and hit the jackpot when the scope of the attack ended up being larger than usual.