Farin Falmuth is known for his get-rich-quick schemes, but this is his most famous one. It started with a simple observation in the Player's Handbook (or in the marketplace, if you want to stay in-character); a single live chicken costs 2 copper pieces. A chunk of meat (in this case, a butchered chicken) sells for 3 silver pieces. That's a profit of 28 copper pieces, quite a substantial sum for a street rat!
One chicken will lay an egg every day, which can be sold or used for food even if they aren't fertile. So, Farin came up with the idea of buying as many chickens as he could with his newfound gold from Tarnade Keep, selling half the eggs, letting the others hatch and grow, selling three-quarters of the grown chickens to the butcher's, and watching the profits grow.
Of course, the plan has an obvious hole; the Falmuths have no place to keep chickens, especially not the 30-50 chickens Farin was planning on buying! Plus, they would soon be up to their ears in eggs and chickens. His sister Marin quickly shot the idea down as being stupid, but Farin still believes it could make a profit. It's highly doubtful the plan will even get off the ground, though, considering Marin's opposition and the street rats' discovery of the more lucrative adventuring career.
Whenever Farin comes up with a crazy plan, Marin has a tendency to roll her eyes and say "This had better not be as harebrained as your chicken scheme was." Lately, she said it in front of Team Stormblade, which led to them asking about the infamous plan. Farin's response to hearing his moneymaking scheme lambasted?
"Okay, okay, no chickens. …. How about pigs?"
(This was shot down just as quickly.)