The problem with trading is that when we purchase some goods we should wait for 4 hours to pass.Some we work and we dont have this comfort.So we go to sell the goods the other day.Please make trading mechanism with some way that the good we buy do not lose their profit.

You don't need to wait for four hours, you need to wait for the next cycle (if the goods in question are going to rise/hike).

The cycle changes at 2, 6 and 10 (and 14, 18, 22h) EDT, so if you buy goods you know will rise at 5pm, you can sell them in the next hour.

Or at 9pm and sell them at 10.

But you can also buy items priced low and sit on them for a few days waiting for them to rise in price.

(Or buy items that were going to rise and then forget about the until a few days later and you get lucky they are maxed out now)

Now, depending on your exact schedule, this may not work.  For me, I can only scout after the 6pm reset and let others know if the rumours are true, because I need to be logged off at 10pm.  But the cycle before that works for me, as long as I can rely on others to verify the rumours while I'm at work.

Step #1: Buy the cheapest trade goods from point A ( Example: Balenos)  to point B ( Mountain of Eternal Winter)

Step #2: Check The order contract every few hours for a price increase.

Step #3: When the price increases, go connect the nodes and transport the goods from Point A to point B.

Step #4:  Enjoy your 20-30 mil profit.  GJ for making 30mil an hour.....