i cannot find why hotels in Madrid charge 2-3 times more than the usual rates at that time.

Lots.
October 12 is Fiesta National de Espana, parades and such.
Also in October, Feria de Otono, big bullighting event (I hope the bull wins)
Festival de Cine.
World Press Photo Exhibition, most popular travel photo event in the world.
Architecture Week.

Lots of trade shows in October.

Thx

I visited Madrid in the past around the same time bit did not notice
the spike in hotel rates just for those days...

Airbnb has dozens of apartments available from $75-125 a night for that period.

What Alec said, but a little more specific info: a big pharmaceutical trade show and convention
https://www.cphi.com/europe/

Do not choose airBnB, The city council are thinking about bring in draconian laws to stop the renting of homes to tourists.
Question is when and just how strict they will be.

It is my understanding that the new rules would not go into effect until November; and then they will be appealed. And there continues to be a disagreement between the planning department (which has created the regulation) and the city council which, in deference to the 23,000 apartment owners affected, has taken no action. If I were looking for an October rent in Madrid, I know I would be welcomed with open arms by many landlords. This is a difficult situation where the argument is that airbnb has lifted local rents, and made it hard for some looking to live there vs. the many retirees and others who supplement small incomes with the income from the tourist rentals.

Did you read what I wrote? there is no fixed date. That is it.
As for the bleeding hearts of the sharing society platform. It is utter Billhooks.
Read what they have found out in the Spanish Balearic Islands
https://mallorcadailynews.com/2018/0...e-despite-ban/

"Did you read what I wrote? there is no fixed date. That is it. As for the bleeding hearts of the sharing society platform. It is utter Billhooks."

Yes. Did you read what I wrote? My information came from a current Spanish newspaper. "Billhooks"?

Airbnb has its haters. You obviously are one. Perhaps you are a hotelier that has been adversely impacted. If so, you have my sympathies. I used to own a hotel, so I understand.. The difficult job for city officials is that sharing platforms from Uber to airbnb are disrupting things, but you also have to consider the wants and needs of the general public. And, young people, the future of our society, seem to have embraced this new way of doing business. As a consumer, I have dozens of great experiences with airbnb, and have met many wonderful landlords. Our 6-week European trip this fall includes 11 airbnb's, one Homeaway and a coupe apartments through booking.com.

>>Perhaps you are a hotelier that has been adversely impacted. <<

Oh come on. Airbnb started out a s simple 'shared economy' . . . a step above couch surfing. Fine. But that isn't the situation now.

It has morphed into a mega (MEGA!!) listing site and a lot of what they list are illegal rentals. Nothing 'Mom & Pop about it. Paris and Venice, and Amsterdam and Carmel, and Santa Monica, and hundreds of other places are fed up. They are the gorilla in the room and I have no problem them being regulated until they either play by the rules or implode because more and more municipalities ban short term rentals.

I agree it has become a MEGA operation. They are doing something right, and there is obviously a huge demand. And, they are being regulated in many places, and I have no problem with that. In all our many dozens of rentals the last several years, I believe most, if not all, have been legal rentals. In some cases, the "illegal" units are being offered by people who feel burned by what they feel are overly restrictive or anti-tourism regulations and rented to people who prefer that type of lodging to hotels and B and B's. Our kids and their friends are big travelers, and all go to airbnb first. Based on that, I suspect that they will have a strong voice as the marketplace and local regulations sort it out in the coming years.

Thx you all for interesting info

Yes I do not like AirBnB because when it came to a problem I had with a listing they never gave any support what so ever. The renter wanted personal details that cannot be asked for in the country we were wanting to stay in. This was about 12 years ago.
Never bothered with them since. It took a lot of emails to reserve the apartment too. All a waste of time.
Whereas with Booking choose and reserve. Great back up from the offices.
More bad news for AirBnB
https://www.wired.com/story/the-airb...rd-of-by-name/
https://www.theguardian.com/technolo...afety-risk-mps
https://www.reuters.com/article/us-e...-idUSKBN1K613F
Never let your house out via AirBnB
https://www.news.com.au/travel/trave...e555c71d69e505
https://phys.org/news/2018-08-ny-may...wn-airbnb.html

It is just UBER of the rental world. No matter how you paint it is a service that is unwanted by those who lives it affects.

PS being a hotelier I could list on there, but I value customer service of the booking portal too much to rush to this one.