bitcoin by its very protocol has a 4 year cycle.. so dont blame everything on US elections.. bitcoin has its own economics

after each halving is a revaluation of the speculative window whereby along with other metrics of mining costs the markets move and cause a ATH

at the moment using world costing of mining, the cheapest being $60k where no one can obtain bitcoin for less so no one wants to sell for less if the market dipped
and premium being $350k where who would dare buy for more if everyone on planet could mine for less.

so the market speculates within this value/premium window (which grows over time)

the ATH season is usually the next calendar year after a halving. so please dont bring trump into it as being the reason for reaching a new peak this year

...
now to answer your questions

no the market is not priced in for the ATH. $110k is not the ATH for this cycle.. we are yet to have the ATH, the ride has not run, the show has not begun, buy your tickets before they run out and enjoy the ride

the inauguration may cause 1-2day of drama that translates to price movement, but is not an impact factor of a multi-month bull leading to ATH.. but it does mean expect maybe some price movements this weekend to midnext week. .. but thats just normal drama

when everyone is buying who is selling?: well anyone thats in profit.. and also people just arbitraging their same stash by riding the different market order books to rinse the opportunities
in short if you sell btc for usd, you then buy altcoin with usd, then sell altcoin for btc and repeat) meaning each sell does not need to be a new persons stash but the same whale repeat selling via arbitrage
but in the same game.. whales can also buy bitcoin via usd, then sell btc to altcoin, then sell altcoin for usd, then use usd to buy back into btc
sell pressure to keep price down/lower price: [BTC->USD][USD->ALT][ALT->BTC]
buy pressure to keep the price up/raise price: [BTC->ALT][ALT->USD][USD->BTC]

People who has the fund and the courage to play with the Bitcoin market often times create a strategic selling in order to make more profit.  If you are asking who are selling in time of the bull run, it is obvious that people are taking profit.  For example, when Bitcoin reaches $100k+, traders who bought Bitcoin at lower price is surely selling to take profit.  Sometimes there are instances where huge holder of Bitcoin make strategic sales in order to pull down the price of Bitcoin and later on buy at a lower price to either bag a profit or bag more Bitcoins.

About the inauguration of Trump and its effect on Bitcoin, I believe Trump had been one of the icons of Bitcoin since he is so open in supporting Bitcoins and his inauguration will surely give hype to the Bitcoin market.  We have already experience an increase of Bitcoin price while the inauguration of Trump is getting closer.

Where you're wrong is that's not erratic what so ever for bitcoin, nor did it ever hit 110.  was like 107ish and we are at what, 104.. Take a look at popular stocks, like Nvidia, it's up and down 4-5 daily often.  (it's overhyped with "AI" propaganda , since AI doesnt exist, or AGI, to be technically exact.

Trump is also not real bright.  Just a fact.  That exchange he's opening, DeFi exchange.. that's an on and off ramp for pure scams.  He doesn't know what a crypto wallet is (let along the diff types of wallets) and his crypto czar is a venture capitalist with NO programming or cryptography background what so ever. 

That said doesn't mean good things aren't still coming, but take anything and everything he says with a very large grain of salt.  What more could he do to make btc go up really?

I don't see a reason on why this should be a concern, since we can't have the market price fixed in one place, but through its volatility there comes the demand for buying and selling, we already have the bear which dip the market to $89,000 before it now comes above $105,000 and I don't know what else do we want from it than the same pattern it has been using to make everyone have a better entry and exit points respectively, maybe a day to the swearing-in or the same day and at worse after the occasion, we may still have some more highs to set the record new.

even when you are strictly a long-term investor, it is usually hard not to get involved in sentiment as this since this current bull has long been associated with trump more than the usual economic concept of bitcoin cycle that is playing its own rule in what we are currently seeing now and yet a lot of speculators are not basing their analysis from that point of view. for us that are investing for the long term, the price increase is just an added validation that tells that one is on track with regard our investment and even though the bull is already telling on our holding for better at the moment, it is still not enough reason to sell yet. like the buildup to the inauguration has caused this bull, there are chances that after the inauguration, some short-term investors will normally want to take out their profit which might lead to a likely correction but in the end, if he finally implements an order that is bullsih on bitcoin, that will cause another rise that will see bitcoin going to the range of $200k upwards.

In the world of crypto, everything is possible. Maybe it's priced already. Maybe it still isn't and there's still an upside to it.

As for the whales, I don't think they need to hide their intention to sell when they feel that Bitcoin has peaked already. The current resistance is at the $108,000, and I will not be surprised if they will sell at that price again. Who's selling? I can only think of 2 types of sellers right now. Those who bought during the 2022 bear market and selling their assets right now for profit, or those who're only buying Bitcoin for the short term, and they're contented with the profits that they got hence, selling it.

What I believe is that, when we surpass the $108,000 which is the resistance, Bitcoin's price will continue to go up from there.

People who are too anxious to wait for a minute longer and thinks that the current price is the highest price that can be reached. Of course all we can do is predict and assume. These people who sold earlier just got it wrong.
If basically what you are asking is whether bitcoin has already reached its ATH then my opinion is no. We have seen this many times before where people start to doubt whether there will be new ATH after bitcoin doesn’t seem to be rising even when an important event comes close but time and time again it has proven that it never fails to deliver.

It is kind of far fetched to think the proposed Bitcoin Reserve is what facilitated his victory.  I honestly strongly believe it contributed to such a small percentage of his victory that it is not one of THE reasons he won.

Now for the Price Bitcoin currently is worth.  Have you ever seen a Bitcoin rally and how it looks like? It does not look like it has priced in at all.  More over, it looks like a great thing whether it is priced in or not.  Think of it this way,

If Bitcoin has priced in already, it means it is much less volatile than it used to be and the rally is so smooth and normal we do not even notice any more.  Though this comes with a caveat.  If it priced in already, then the percent it increases by every cycle is becoming so low it may not be profitable for Miners to continue their operations.  In that situation, you have to worry about way more than whether a rally is due or not.

If it has not priced in already then the upcoming Bitcoin rally will likely be an incredible ride.  We are past 100 Thousand Dollars a Bitcoin.  These are insane numbers.