On approximately November 18, Bitcoin will split into two chains: Segwit1x and Segwit2x. Because these chains share the same proof-of-work function (PoW) and neither change the difficulty adjustment algorithm (DAA), it is unlikely that both will survive simultaneously.
A complicating factor is the existence of Bitcoin Cash, a fork of Bitcoin which shares the same PoW but has in addition an improved DAA that ensures it can adjust downward in difficulty rapidly as needed in the event of miner evacuation, keeping its block interval at approximately 10 minutes on average. Bitcoin Cash cannot die, but Segwit1x and Segwit2x can both die.
These are the possible scenarios that may unfold starting November 18:`
Bitcoin Cash becomes the dominant chain measured by total PoW, Segwit1x survives with an "emergency hard fork" to a new PoW function or DAA, and Segwit2x dies.
This scenario is widely ignored or ridiculed in the Bitcoin community which is why the current price of Bitcoin is more than ten times the price of Bitcoin Cash. However, this scenario is actually the most likely due to the spectacular gains to be made by miners, speculators and businesses who game this scenario. Anyone who is in a position to cause the flippening can increase their money 10-fold in a month, followed by far higher long-term gains due to the ability of Bitcoin Cash to scale to a global audience.
If this scenario plays out, it will probably happen as follows:
Whales will buy Bitcoin Cash cheap and sell Bitcoin at its all-time highs in preparation for the flippening. Then by leveraging huge amounts of capital, whales will push the price of Bitcoin Cash up and the price of Bitcoin down at approximately the same time as the split between Segwit1x and Segwit2x.
Miners will now be incentivized to switch from Segwit1x/Segwit2x to Bitcoin Cash due to improved profitability, while Segwit1x and Segwit2x both struggle on suddenly far lower mining power. Miners themselves may also be whales and will deliberately cause the incentives to shift for their own double gain.
Segwit2x dies to due no ability to change the PoW or DAA (since that's not a part of the New York Agreement (NYA)).
Segwit1x changes its PoW and survives as an altcoin branded as "Bitcoin". Many in the Segwit1x community are already comfortable with this possibility, and more certainly will be if all of their value is threatened with destruction otherwise.
Over some period of time, Bitcoin Cash achieves status as the longest chain as measured by total PoW and some exchanges and businesses now regard it as being "Bitcoin".
Scenario 2: Segwit2x wins
Segwit2x becomes the dominant chain measured by total PoW, Segwit1x changes its PoW, and Bitcoin Cash survives.
This is the second most likely scenario due to the fact that a vast majority of miners and a majority of businesses have committed to Segwit2x as part of the NYA. However, this scenario is strictly less likely than the above due to the lesser gains to be made. No one can multiply their value by 10-fold in a short period of time in this scenario. And the long-term future is likely to continue to have infighting, high fees, and loss of market share to altcoins - it's better for business if Bitcoin Cash wins.
Note that, even if Segwit1x has a higher price on exchanges at the time of the fork, that does not help Segwit1x much if miners stick to their agreement and continue to mine Segwit2x. See Vinny Lingham's theory about how the minority chain cannot have a higher value.
In this scenario, similar to the above, it is most likely Segwit1x will change its PoW and become an altcoin in order to ensure its chain survives.
Scenario 3: Segwit1x wins
Segwit1x becomes the dominant chain measured by total PoW, Segwit2x dies, and Bitcoin Cash survives.
If the movement from the Segwit1x community is successful, Segwit2x will be prevented from occurring due to the community uprising. This scenario is less likely than the above two scenarios due to the lack of commitment from miners to mine the Segwit1x chain. Segwit1x will probably not survive on ~10% of mining power due to excessively long block times for several months. Trolling on social media is not a substitute for mining power.
In this scenario, Segwit2x completely dies as no parties in the NYA agreed to change the PoW function or DAA in order to allow it to survive.
This scenario can be encouraged by whales. If whales specifically desire to make Segwit1x the dominant chain, they can buy Segwit1x. If they are able to sustain a high price of Segwit1x due to a flood of capital that lasts beyond any insecurity, the miners are incentivized to switch back over from Segwit2x. However, this requires vastly more capital than the scenario in which Bitcoin Cash wins because the market cap of Bitcoin is more than 10 times that of Bitcoin Cash. Rational whales who actually want Bitcoin to succeed would prefer the Bitcoin Cash scenario.
Other Near-Term Scenarios
There are other scenarios that are logically possible, such as the co-existence of Segwit1x and Segwit2x with no further hard forks, but they are unlikely. I believe one of the above three scenarios will almost certainly be the scenario that plays out in November.
Long-Term Scenarios
Note that if Bitcoin Cash does not achieve majority mining power and total accumulated PoW, the situation will continue to be unstable past the November 18 fork. Over the long-term, Bitcoin Cash can both achieve a larger user-base than Segwit1x/Segwit2x and, because it has a better DAA, it can't die, and will therefore continue to be a thorn in the side of Bitcoin until it ultimately acquires majority mining support and becomes labeled "Bitcoin".
However, things could easily change long-term to affect these probabilities. For instance, if Bitcoin changes its DAA to be similar to Bitcoin Cash, then Bitcoin Cash's advantage will go away and the mining dominance of Bitcoin will continue.
Behind the pay wall you will find information about how I am personally allocating my funds in this situation.