yodacaia

1. sell forward 500 cs ag 1050 usd
2. discount (finance) this to t0 485.44 cs and 1000 usd
3. convert 485.44 cs at spot 970.78 us
4. net us t0 you get 29.126 usd profit

this is mathematically equal to
(2.1/1.05 - 2/1.03) x 500

the profit is upfront and I convert forward only 1050 usd and equivalent cs

here I also borrow 1000 usd but need only roughly 970.78 usd to convert at spot to cs

if I wanted to invest my own usd into this (meaning I dont need to borrow anything) I would invest only 970.78 and I would receive in 1y 1050 usd = return = (1050 - 970.78)/970.78 = 8.16 pct

if say topher wanted to invest his own usd he would invest 1000 usd in t0 and receive 1081.5 in t1= return on his investment = 8.15 pct

same pct return (difference due to rounding)