Tether has announced plans to issue USD₮ on the Bitcoin network through RGB. At the same time, new BRC-20, Ordinals, Runes, and Alkanes projects continue to emerge. Bitcoin asset protocols, once discussed mainly by a small group of developers, are now attracting increasing attention from ordinary users. The Bitcoin ecosystem is becoming more active than ever. A Simple Guide to the Main Bitcoin Asset Protocols 1. RGB: Bringing More Complex Assets to Bitcoin Tether has announced plans to issue USD₮ on Bitcoin through RGB. This could mark an important change for the Bitcoin ecosystem. Bitcoin is no longer being used only to transfer BTC. It is also becoming a platform for stablecoins, privacy-focused assets, and more complex applications. RGB is trying to answer a fundamental question: Can Bitcoin support stablecoins, private assets, and more advanced applications? RGB divides the responsibilities between Bitcoin and the RGB layer. Bitcoin is responsible for security, consensus, and final settlement. RGB is responsible for asset states, ownership, and application logic. The complete transaction data of an asset does not need to be written publicly into the Bitcoin blockchain. Instead, the participants involved in the transaction store and verify the relevant data themselves. This is the core idea behind RGB: Client-Side Validation. In simple terms, only the people involved in a specific asset transaction need to verify the complete information related to that transaction. This can reduce the amount of data placed directly on-chain while giving asset transfers stronger privacy. Current examples in the RGB ecosystem include USD₮ on RGB, the early community asset $PPRGB, and infrastructure projects focused on wallets, trading, and payments, such as BitMask, LNFI, KaleidoSwap, Darkhorse, RGBMap, and Utexo. 2. Ordinals: Bringing Digital Content to Bitcoin Ordinals are one of the important starting points of the Bitcoin asset ecosystem. They allow images, text, and other data to be inscribed onto satoshis, the smallest unit of Bitcoin. Through this process, Bitcoin began to support digital artwork and collectibles. Bitcoin Puppets, NodeMonkes, and Quantum Cats are some of the better-known Ordinals projects. Ordinals made the market realize on a large scale that Bitcoin block space could do more than record transfers. It could also carry digital content. This approach also has clear limitations. The data is written directly into Bitcoin blocks, which takes up block space. Minting and transferring costs can also be affected by network congestion. Ordinals are better suited to digital collectibles and art projects. Supporting complex asset logic is much more difficult. 3. BRC-20: A Token Experiment on Bitcoin After Ordinals appeared, BRC-20 took the next step by asking: Can Bitcoin issue assets similar to Tokens? BRC-20 uses inscriptions to record Token deployment, minting, and transfers. Users write inscriptions in a specific format. Wallets, trading platforms, and indexers then read this information and use it to maintain a set of asset accounting rules on Bitcoin. This was the first time Bitcoin saw a large-scale market of Tokens that could be traded, transferred, and widely distributed. $ORDI is the most representative BRC-20 asset. Projects such as $SATS and $RATS also helped drive the development of Bitcoin Meme culture. More recently, $SHHHHH has combined BRC-20 with the concept of Bitcoin silent payments. It attempts to use one-time addresses and privacy-focused payment mechanisms to make different minting activities more difficult to link through public addresses, adding a new narrative to the BRC-20 ecosystem. BRC-20 gave many ordinary users their first clear impression that: Bitcoin can also have Tokens and its own Meme asset market. 4. Runes: Making Bitcoin Memes More Native After BRC-20 emerged, the Bitcoin ecosystem saw a large number of Tokens and Meme assets. As more users entered the market, another question appeared: Can Bitcoin issue fungible assets in a simpler and more native way? Runes was proposed by Casey Rodarmor. It mainly uses Bitcoin’s UTXO and OP_RETURN structures to record asset issuance and transfers. Compared with BRC-20, which relies heavily on inscription data, Runes is designed to fit more closely with Bitcoin’s original transaction model. This makes Runes especially suitable for Memes and other fungible assets. Among them, $DOG is one of the most representative Runes assets. It was distributed through the Runestone community airdrop and carries a strong Bitcoin-native narrative. It also helped more ordinary users discover the Runes ecosystem. Other recognizable names include $PUPS, $RSIC, $MIM, and UNCOMMON•GOODS. Runes gives Bitcoin Meme assets a clearer and more native issuance model. 5. Taproot Assets: Bringing Stablecoins to the Payment Network Taproot Assets follows a different direction. It focuses more on stablecoins, payment assets, and the Lightning Network than on NFTs or Memes. The central question is: Can Bitcoin become the underlying network for stablecoins and multi-asset payments? Taproot Assets is promoted by Lightning Labs. Its main goal is to connect multiple assets with Lightning’s fast and low-cost payment experience. In the future, users could benefit from Bitcoin’s security and settlement while transferring assets more quickly through Lightning. Stablecoins, business payments, and cross-border settlements are all areas where this technology could be useful. Its challenge is that wallets, trading platforms, issuers, and merchants all need to support the ecosystem together. A protocol can work technically without being simple or convenient for ordinary users. For this reason, Taproot Assets is best understood as infrastructure for Bitcoin-based financial payments. Conclusion Each of these protocols expands a different capability of Bitcoin. Together, they are helping Bitcoin move from a simple value settlement network toward a more complete asset ecosystem. Among these routes, RGB deserves particular attention. Tether’s plan to issue USD₮ on Bitcoin through RGB shows that RGB is entering the larger stablecoin and payment narrative. At the same time, wallets, trading platforms, payment tools, community assets, and developer infrastructure are continuing to emerge around the ecosystem. As this infrastructure becomes more mature, RGB could become an important layer connecting Bitcoin’s security with digital asset applications. The Bitcoin ecosystem is only beginning to expand. And RGB may be standing at a critical point in Bitcoin’s next stage of development.