Wall Street dudes will tell you, pretty much without exception, that you should never fall in love with a stock. If an investment hits your price target — and certainly if it shatters your price target — take your profits. It's better to sell shares while they're on the way up, not after they've crested, when everyone is looking to unload.

And clearly we all need to listen to Wall Street dudes, because they've never [expletive] anything to [expletive].

There's an obvious fantasy tie-in here, because experts are always discussing the importance of buying low and selling high. This is a concept we mention all the time, but we're often reluctant to attach specific names to the conversation — if you're vague enough in your advice, then you're never verifiably wrong.

But that won't be an issue with this particular feature, because today we're discussing just one name: Robert Griffin III, rookie quarterback for the NFL's top-scoring team. Three weeks into the season, Griffin leads all players in total fantasy points, by a significant margin.

Here's the overall top-five in Yahoo! public scoring:

Robert Griffin III — 81.78 points

Matt Ryan — 73.52

Ben Roethlisberger — 68.36

Drew Brees — 65.06

CJ Spiller — 64.20

RGIII has actually been so productive that if you ignore his passing stats entirely, leaving only the rushing totals (209 yards, 3 TDs), he still ranks ahead Jay Cutler, Josh Freeman and a handful of other QBs in year-to-date fantasy scoring. Based simply on his rushing numbers, he'd be the No. 12 running back in our game. He's been ridiculous, an outstanding fantasy asset. If you haven't been thoroughly impressed, then you probably haven't been watching.

Griffin is also, in my opinion, the most obvious sell-high candidate in fantasy right now, a name-your-price trade chip. If he's on your roster, I'd suggest that you at least explore the market. I've flipped RGIII twice over the past 10 days, and wish I had more shares to sell.

My first Griffin deal was a one-for-one trade in a 16-teamer, returning Darren McFadden. In that league, my starting quarterback is Matt Ryan, and DMC replaces Ryan Williams in the active lineup. In the second trade, I acquired Mike Vick, Steve Smith (the useful one) and Santonio Holmes in exchange for RGIII and Pierre Garcon. Vick is merely a back-up to Drew Brees on that team; the addition of Smith and Holmes means Justin Blackmon can take a seat, which thrills me.

In both deals, the goal was to address a glaring weakness in my every-week starting roster by trading from a position of surplus. Make sense?

Let's hope so, because that should be a primary objective in any trade you ever make.

I'm assuming that a majority of RGIII owners, like me, drafted him as a high-end back-up. He was usually a best-player-available selection, made after you'd sketched in most of the starting roster, quarterback included. And even if you targeted him as a fantasy starter, you likely took a second respectable QB soon after. This could mean that RGIII's contributions are, to some significant extent, replaceable. If you toss his name on the trade block now, today — with an appealing match-up on the horizon (at Tampa Bay) — you're basically guaranteed to receive a pile of interesting offers.

There's a very good chance you'll be dealing at or near the peak of the RGIII market, too.

This seems like the right time to once again mention — before we go any further down the trading road — that Griffin has been phenomenal. Fantastic. Brilliant. There's no arguing otherwise. His three-week performance has definitely not been fluky. A reasonable case can be made that he'll maintain his current spot at the top of the ranks.

But when you attempt to forecast his rest-of-season fantasy contributions, it's important to acknowledge these two key details:

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