http://goarticles.com/article/How-to-Value-Gold-Stocks/5708614/

For the purpose of this particular report we worked with 136 stocks, the vast majority of which are primarily listed on the TSX and its Venture exchange.

As a reminder, here are the three broad NI43-101-recognized resource categories we use:

1. Proven & Probable (P&P): These are bankable mining reserves - basically Measured plus Indicated resources with established commercial value. What most producers actually mine.
2. Measured & Indicated (M&I): These higher-confidence categories have been sufficiently drilled to establish their geometry along with continuity reasonably well.
3. Inferred: The lowest-confidence category, based on just enough drilling to outline the mineralization. In many cases, Inferred resources, as the name suggests, are really just guesses at what might actually be there.

Last December, when we last ran the numbers, here was the result:

1. Inferred: US$21.90 per ounce
2. M&I: US$44.30 per ounce
3. P&P: US$230.40 per ounce
Gold has since risen by 10.8% (as of 5/2). The TSX-V, exactly where many of our gold juniors trade, has seen its index add almost 6% within the same timeframe. No surprise valuations meant for the three resource categories came out significantly higher:
1. Inferred: US$61.20 per ounce (up 179.5%)
2. M&I: US$69.30 per ounce (up 56.4%)
3. P&P: US$232.70 per ounce (up 1%)
4. Average value of global resource (total of P&P, M&I, and even Inferred): US$87.10 per ounce.

Keep in mind that that time we are looking only at the companies with an estimated gold resource; silver and even other metals credits (or burdens) are largely out. That appears to have influenced the valuations to the upside, apart from the movement in the price of gold.