I'm pretty sure the listed prices are incorrect. I'm only seeing ~16% profit on tier 2 (buy 60.46Dc worth of shares, make 9.57) and ~8% on tier 1 (buy 70.13Dc, make around 5.88Dc)
(Buying when it dips below the line below the mid line, and selling a bit above the line above the mid line, which is just about as extreme as it typically gets.)
Tier 2 that's buying at a bit less than 204.00 per and selling at a bit over 264, which unless I screwed up my math, should be at least a 30% profit.
Tier 1 that's buying at a bit less than 14.00 and selling at a bit over 16, which should be over a 14% profit.
Unless the game is trying to simulate an almost 50% short term capital gains tax... The numbers aren't adding up.