The one who sweat blood are the be ones who play the the theoretical market. They play it like a commodities game, buying and selling contracts that represent physical product they never see. I have no contact with anyone involved with that, but the ones who deal in bars and coins that real clients have to sell seem pretty laid back. The more they know what they are doing, the more laid back they seem.
I was in the shop of one of them once when a woman brought in a big (30 gram) gold coin with Arabic script on both sides. He called me to the counter to ask if I had any idea what it was. As it turned out, I did. She asked what he would offer for it, and I told him he could probably get $6000 or $6500 for it. He offered her about $5250 (in euros), and she gasped in surprise. I was pretty sure of myself,, so I asked what was wrong. She said nothing, but the other shops nearby had. All had offered about $1300, so how could I offer $5250? I asked if the other shops had been able to tell her what it was, and she said no, they had no idea (as did my pal in whose shop I was in). I explained that it was an Egyptian 500 Qirsh of 1876 (1st year of Abdul Aziz, Islamic year 1293). It wasnt in perfect shape , but better than usual, thus the higher price. The woman went home with (in euros) $4000 more than she expected, my friend was looking at a $750 profit when he sold it, and I was looking forward to a fancy lunch st a local Paris restaurant next time I was in town. I asked her where she had found such a specimen, and she said her grandfather had brought it back from Egypt nearly a century ago, which made perfect sense. There are fakes of these coins, but part of my job is to detect counterfeit money, including older forms, and I recognized her piece as genuine.
So, not is it not always hi pressure, sometimes, it is downright fun.