The deal is not capped at $50, $50 was just an approximate valuation.

The key # is $26.84 -- that's the DIS price at the time of the announcement. If DIS is exactly $26.84 at the time the merger goes through, the deal values out to $50. If DIS is less than $26.84 at merger time, the deal will be worth less than $50, and if DIS is higher, it will be worth more than $50.

However, the deal also adjusts on the downside -- the DIS shares must be at least 40% of the total valuation. If DIS were to drop below $26.84, the exchange ratio would increase from .7495, and the $30 would decrease accordingly.

On the upside of $26.84, both the $30 and .7495 numbers are locked in. There's a table in their filings which maps the numbers out, but a handful of upside approximations:

DIS $28.50 = value $51.24
DIS $29.00 = value $51.61
DIS $29.50 = value $51.98
DIS $30.00 = value $52.36

The reason MVL trades for less than $51.61 if DIS were at $29 today is due to an arbitrage spread -- since there's slight risk the deal won't go through, there's a 1.5% incentive to hold on through the deal vs. selling today. That spread gets smaller as the deal gets closer to happening -- it was around 4% at the start of this.

-KJ, thinks the cap gains tax should be even less than 15% on shares held since 2000... :)