Underlying Tiers

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Overview

Assets are classified into three tiers based on their liquidity. Tier assignments follow Coinbase International Exchange’s perpetual futures tier classification and determine:

• Rate limits — see API Rate Limits
• Multicast channel assignments — see Multicast Channels

Tier classification is based on the base currency of the underlying index. All underlyings sharing the same base currency belong to the same tier — for example, both BTC_USD and BTC_USDC are Tier 1.

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Programmatic lookup

The product_group field on public/get_instruments reports this classification per instrument (values such as BTC, ETH, TIER_2, and TIER_3), so clients can drive gateway and channel routing from the live response instead of hard-coding the tables below. The field is documented on both the standard JSON-RPC and Starbase REST versions of the endpoint. product_group is a per-instrument routing classification used for gateway and multicast-channel assignment. Rate-limit overrides use five product tiers (BTC, ETH, Tier 2, Tier 3, and RWA + Pre-IPO). Within a product tier, options and futures share the same rate-limit buckets.

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Tier 1

The most liquid assets. Tier 1 instruments have dedicated multicast channels and the highest allocated rate limits.

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Tier 2

Established assets with moderate liquidity. All altcoin options are Tier 2 regardless of the underlying’s tier.

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Tier 3

Lower-liquidity assets.

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Tier Change Policy

Tier assignments determine which multicast channel an instrument belongs to, so changing a tier has operational consequences for trading clients. To give clients time to adjust:

• Tier changes are made only during planned deployments.
• Affected clients receive at least one week’s prior notice before any tier change takes effect.