Reinvestment
Reinvestment means buying new miners with the income from the ones already running. The right question is not 'should I expand' but 'what earns the most per kilowatt'.
How to think about reinvestment
What usually limits you is not money but power: outlets, breakers, cooling. So reinvestment is counted per kilowatt, not per miner: a new efficient ASIC in the same spot can bring more than another one of the same kind next to it.
Timing matters as much as the amount. Hardware prices follow the coin price: in a heated market an ASIC costs twice as much as in a dull one, while a terahash earns the same. Buying at the peak of euphoria is the most common way to turn income into a loss.
Count with depreciation. Income minus electricity is not profit yet: the ASIC gets cheaper with every month of work, and the honest return only shows after that line is subtracted.
You don't have to reinvest everything. Taking part of the income out into coin or cash is a strategy too, especially before a halving, when the older hardware generation may not live long enough to break even.
The short version
| What to count in | income per kilowatt, not per miner |
| What limits you more often | power and cooling, not money |
| When buying is bad | at the peak of coin and hardware prices |
| What to always subtract | electricity and depreciation |
| The alternative | cashing out part of the income, upgrading instead of expanding |
How to make the decision
Work out the fleet's current J/TH and compare it with the new generation: upgrading the hungriest spots often beats adding another outlet.
Check the infrastructure: spare amps on the breakers, cooling headroom in summer, space in the rack. A miner without a ready spot is a box on the floor.
Estimate the payback period at your rate on a calculator, and honestly add the hardware price drop over that period.
Keep a repair reserve: fans, power supplies, one board at the shop. A fleet with no reserve stops at the most expensive moment.
Example of the logic
You have a free 3.5 kW and half a year of income. Option one: another last-generation ASIC, cheap, but 34 J/TH. Option two: sell the two oldest, add the income, and install one new miner at 17 J/TH. The second option gives more terahashes on the same watts, and in summer it is the only one that does not run into the cooling limit.
Related terms
Where to go next on the site
Numbers
Hardware
- ASIC Miner knowledge base
- Antminer S21 tool
Questions and answers
What share of the income should you reinvest
There is no universal number, there is an order: repair reserve and electricity paid ahead first, then upgrades, then expansion. Anything on top of that is a question of your faith in the coin.
Reinvest or hold the coin
Those are bets on different things: hardware earns on hashrate and loses value, the coin is simply volatile. Mixing them in one decision is worse than splitting them: mining on its own, savings on their own.
Should you expand before a halving
Carefully: the block reward halves, and old hardware is the first to fall past break-even. Before a halving the strongest argument is for an efficiency upgrade, not for quantity.
How the terms connect
Every link in the chain is clickable. Orange marks where you are now.
Looking for an ASIC miner
The catalog holds 212 models. You can compare them by hashrate and by joules per terahash, then plug your own rate into the calculator and see what stays in your pocket.
Page written and checked by Denys Klimchuk. Updated .