this is from a mineweb article on investing in juniors/explorers...the rest of the article was kinda long and fluffy but i got a kick out of this part...it's easy to see where gnh is located in the 4 types of properties.

Stage and risk

Greenfield (GF) - early stage exploration - the most upside (and by far the greatest risk) comes from buying a junior when they are exploring and make an initial discovery. Great drill assay results can send a juniors share price skyrocketing. The reverse can also be true. Junior explorers, the greenfield plays, are the riskiest plays by far. Strike out on assay results and it could be goodbye to a share price rise for a very long time - till the company finds another project they can work on. If you're buying into this kind of play make sure the company has another fallback project in its portfolio.

Post Discovery Resource Definition (PDRD) - these companies have already found something, the share price has settled back after the initial discovery (never chase a company whose share price has already exploded, the share price has had its run, for now the moneys been made. I try and enter after the excitement has died down and the share price has settled back) and the company is going in to see what they have and hopefully produce a 43-101 compliant resource estimate and build upon it. The risk has been greatly reduced, the waiting time for a discovery non-existent and the reward very nice considering the much lower amount of risk.

Nearer term producers (NTP) - those further down the development path towards a mine. Because these companies are well advanced along the development path a lot of the guesswork about grade, size, costs and metallurgy have been taken out of the equation for us. They have done sufficient work to give investors a certain level of confidence that their project will successfully move towards being a mine.

The later stage companies (those doing feasibility studies, permitting and money raising) can have an excellent entry point for investors - they often enter a quiet period when they are doing the advanced studies and raising money to go into production. They often base (a flat share price) for quite a while through this period - possibly a good time for accumulation of their shares if you believe in the story. After the money is raised for production investors can see they are going mining - cash flow is just over the horizon - and the share price will often break out of its trading range.