Corporation Help

I have many types of corporations in my country but what is the best type of corporation to build that will

rise in market price the fastest?
uses the least raw materials?
is always in demand so it will always make sales?

There aren't any corporations that can simply do that. In my opinion the best corporations are a combination of some stable high tech and industrial corps. Some products like household products and computers are examples. There are some products that are almost always in demand with rare cases of supply. Other corps like Airforce, Defense, and offensive weapons Maintenance can have the highest profitability BUT they can also lose just as much. It's a gamble with them and I don't suggest it. As their demand/supply is usually close and some require special materials you can only get on FB like stealth bombers for airforce and you'd have to supply your Land Based Cruise Batteries for offensive maint. I suggest you look at other top player countries to see what they have and make your own judgement. Heck check my main on KB Alstroemeria #3 finance rank. All of my corps besides Airforce maint make solid profit. Should see it in the president hall of fame. Really though. I suggest looking at top 10 countries on your world, big ceos as well and hall of fame members. I could give you a list of corps I always build, but it would be too long. Just try to stay away from weapons corps. Focus on high tech and industrial. Some services, construction and mining corps like oil and potassium wouldn't hurt either. Hope this helps. Your supply and upgrades can also have a very big impact on profitability. Taxes and profit sharing does not effect profit, however it has a large effect on corporation value.

Thank you for your advice, I find the corporations that make the most profit are household products, home equipment and services. It seems the market situatíon for services is always in need however it time for corporations to make big profits unless you get the boosters, bit to boost 65+ corporations is alot of gold coins so I guess imam play the waiting game.
Also anytime I make a car manufacturer they never seem to make profits for me, the income is ALWAYS less than the raw materials used plus salaries, am I doing something wrong or am I being impatient???

Check market price for cars. Those have been a buyers market for some time on LU and other worlds.

THE MARKET PRICE FOR CARS IS VERY CONSTANT. AND THE CORPORATION IS STILL MAKINKG LOSSES THE ONLY REASON I DONT GET RID OF THE CORPORATION IS TO SATISFY MY COUNTRYS DEMAND FOR CARS

Your country will buy supplies off the market as needed. There's no need to have your own production.

Yeah, the car price is constantly at the minimum possible. You see, the market price fluctuates above and below the "base price" to a possible max and min. You can see this base price if you go to the trade->"products in stock: buy/sell" page and bring up the page as if you will purchase a certain product. The base price on cars is 11,700. The current market price on lu is 9,453. If the market price is below the base price you will unlikely make money producing that product.

If you're contracting the full car corporation, theres no need to worry as you're buying your own product. So the profit/loss won't effect you I believe. The corporation won't be as valuble, but you're paying yourself by population spending on cars. If you're going for local market score it's not an awful idea. Just don't sell them on the market. The only real expenses you'll be paying is materials. @Al Sadius correct but if General LDN is trying to get some local/common market score for gc reward might not be a bad idea tbh.

It's more than the material costs when you make a product that is unprofitable to produce. There is an opportunity cost as those same workers could have produced a product that is in demand on the world and is pricier as a result. Just an example, on lu, it is better to make gasoline and buy cars from the market than the reverse.