From what has been said so far: Olin will benefit from the larger chlor-alkali & bleach sales area. JV makes Olin a much more vertically integrated company with more outlets for chlorine. Low cost Dow plants will help bottom line due to scale. Olin will now be a bigger, more diversified, and stable company with less downside risk.
The bad side: high cost plants are now ripe for shutdown; demand/growth for all commodity products is still limited; small 2% growth potential if Olin remains in commodity chemicals; ECU prices/demand still tied to economy; continued high capital outlays for plant maintenance and upgrades (most of the plants are decades old); vulnerable to higher energy costs (just a matter of time until $100 oil again); captive use of Cl2 but still a need to dump caustic - continued pressure on ECU prices; all new ECU sales will still mean high shipping cost; legacy environmental costs and other legacy costs for pensions, health care, legal, etc.
Net - Olin will be a bigger, slightly more profitable company. But still a commodity chemical business. SSDD.
Dow is the winner with less capital demand and continued captive supply chain. Olin will make significant gains only if they continue with vertical integration into ECU based products. Otherwise still just a cyclical chemical business with many more outstanding shares. I see future stock prices in the 10-14 PE ratio, $25-40/shr vs. recent 20-28 range. 2-3% dividend continues. A HOLD for now until the dust settles and we see the net impact. Congrats to long term Olin holders and hope the May 30 Call holders are the subject of immediate SEC investigation and persecution.