Sia has a second cryptocurrency called the Siafund (SF). 3.9% of all successful storage contract payouts go to the holders of the Siafunds. There are 10,000 siafunds in total, and all 10,000 are completely premined. Sia's parent company, Nebulous Inc., holds 8835 of these Siafunds. The remaining Siafunds were sold in a crowdfund which helped finance Sia's early development. The primary goal of Siafunds is to provide a way to finance the development of Sia without relying on donations or a premine. More people using Sia means more funding available to hire more developers.
Standard transactions are not subject to the fee, and neither are failed storage contracts (where the host was offline or lost the file).
(source: [ANN] Sia - Decentralized Storage)
Siafunds are stored on regular wallet addresses. When someone sends you a Siafund it will show up in the UI under your normal Siacoins. Your Siafunds can also be recovered from the wallet seed just like Siacoins.
When you have Siafunds in your wallet they are statically collecting fees. These fees come from renters who are spending money on uploading, downloading and storing files.
If you have Siafunds in your wallet you can view your claims with the following siac command:
siac wallet (or just
wallet in the GUI terminal). It will show an output like this:
Siafunds: 2 SF Siafund Claims: 16000000000000000000000000 H
As you can see the claims are reported in Hastings
To cash out your pending claims you need to send the Siafunds to a new address. This can of course be another address in the same wallet, run
siac wallet address to get a new address. When your Siafunds have been sent to the new address the claims will be transferred to the address where the Siafunds came from.
When a storage contract (formally: “obligation”) is completed between a renter and a host the transaction becomes final. The nodes on the Sia network will calculate how much of the money held in the contract belongs to the host and how much belongs to the renter (refunds).
If a contract holds 1000 SC paid by the renter and 1000 SC put up by the host as collateral. When the contract ends 78 SC (3.9%) of the total will be allocated to the Siafunds. That amount is divided over all 10000 Siafunds on the blockchain. Every Siafund gains 0.0078 SC.
Up to now, Siafunds can only be traded on Bitsquare (https://bitsquare.io/) and “over the counter” in our #siafunds Slack channel. Always make sure that you use an escrow for OTC-trading. There are several community members who can help with that, just ask about it in our Slack channel. The price for one Siafund is not fixed and can be negotiated with the trading partner.