Junior mining explained in finance terms

Exploration is an option

A junior explorer spends money on drilling and studies in the hope that a deposit turns out to be a mine. In option terms:

Two consequences follow. First, uncertainty is not only a risk: a project with a wide range of possible outcomes can be worth more than a dull, certain one, because the downside is capped at the money spent. Second, time matters. A licence about to lapse, or a company about to run out of cash, is an option close to expiry.

Outcomes are binary, in stages

Value does not drift up smoothly. It moves in jumps at published milestones: a discovery hole, a first resource, a PEA, a PFS, a feasibility study, a build decision. Each is a gate the project passes or fails.

These are the site's illustrative odds: see why most projects fail and the stage guide. In finance terms, this is a staged-attrition pipeline, much like drug development. A useful first estimate of value is the value of success times the chance of reaching it, less the cost and time still ahead.

Returns follow a power law

Because most projects fail and a few succeed spectacularly, returns are highly skewed. An invented portfolio of ten $1M investments in maiden-resource-stage juniors:

The portfolio doubles its money, but only because of one result. Without the takeover it returns $5M, a loss of half. That is why position sizing and diversification matter more here than picking single winners, and why the median investment loses money even when the average makes it.

Dilution is the cost of capital

A junior has no revenue to borrow against, so it pays for every stage by issuing shares, usually at a discount to the market price and often with warrants attached. Its cost of capital is not an interest rate; it is the share of the company given up.

That cost is highest when the company is weakest: after the discovery excitement fades and before studies prove the economics. A few rounds at falling prices can leave early shareholders with a small slice of even a successful project. See how juniors are listed and traded and why the funding gap exists.

Where royalties sit

Between a bond and a share sits the royalty: a right to a percentage of a mine's revenue for its whole life.

A royalty holder avoids cost overruns and dilution, and keeps exposure to the metal price and to any extension of the mine's life. But on an unbuilt project, it carries the same all-or-nothing risk as the shares. See royalties and streams.

Valuation moves from options to cash flows

Early on, there is no cash flow to discount. Explorers trade on comparable deals, value per resource ounce or tonne, and the size of the option. Once a study exists, the market applies a price-to-NAV multiple: a fraction of the study's NPV that rises as risk falls. By production, the usual cash-flow and earnings multiples apply.

A worked example, using an invented project that would be worth $500M at a funded build decision:

Real valuations sit below these figures, because they also allow for time, the money still to be spent and dilution. But the pattern is the one investors trade on: each milestone re-rates the project.

A translation table

Interactive explainer

• Grassroots
• Discovery hole
• Maiden resource
• PEA
• PFS
• FS
• Build decision
• Building
• Mine

Move along the path

3Stage 3: Maiden resource

Maiden resource

First resource estimate signed by a qualified person. Mostly Inferred, sometimes with Indicated where drilling is denser.

Chance of becoming a mine

About 15% (1 in 7)

Spent so far (cumulative)

About $10M

+$7M since discovery: drilling ~$6M, assays and estimate ~$1M

Drilling

10,000–50,000 m at about 80–200 m spacing

Typical funders

Junior explorers: the start of the funding gap

Show as a table

Milestone	Chance of a mine	Spent so far (cumulative)	Drilling
Grassroots exploration	About 0.1% (1 in 1,000)	About $0.3M Starting spend: mapping, sampling, geophysics	None yet
Discovery drilling	About 3% (1 in 30)	About $3M +$3M since grassroots: drilling ~$2M, surveys and access ~$1M	2,000–5,000 m, scattered target holes
Maiden resource	About 15% (1 in 7)	About $10M +$7M since discovery: drilling ~$6M, assays and estimate ~$1M	10,000–50,000 m at about 80–200 m spacing
Preliminary economic assessment (PEA) published	About 30% (1 in 3)	About $20M +$10M since the maiden resource: drilling ~$8M, metallurgy ~$1M, PEA study ~$1M	Infill toward about 40–100 m spacing, first metallurgy
Pre-feasibility study (PFS) published: Probable reserves	About 45% (about 1 in 2)	About $40M +$20M since the PEA: drilling ~$10M, testwork and environment ~$5M, PFS study ~$5M	Indicated spacing, plus geotechnical, hydrogeology and condemnation holes
Feasibility study (FS) published: Proven reserves	About 65% (2 in 3)	About $70M +$30M since the PFS: drilling ~$10M, testwork and permits ~$5M, FS study ~$15M	About 15–50 m spacing in the early mine plan
Construction decision	About 85%	About $120M +$50M since the FS: early engineering and orders ~$30M, permits and community ~$10M, financing ~$10M	Mostly complete; some grade-control and near-mine drilling
Construction	About 95%	About $500M +$380M since the build decision: plant ~$200M, mine and fleet ~$100M, power, water and tailings ~$80M	Grade control and near-mine exploration
Producing mine	It is a mine	About $1B +$500M during the build: rest of construction ~$400M, ramp-up and working capital ~$100M	Ongoing grade control and reserve replacement

What to take away

Treat a junior as an option, a portfolio of juniors as a venture fund, and each financing as a price paid in ownership. Value comes in steps at milestones, most outcomes are losses, and a few large wins carry the rest. The geology sets the odds; finance sets the price.

All figures are invented for illustration. This is educational material, not investment advice.