Active-Passive Period Segmentation

What is Active-Passive Period Segmentation, and how does it differ from the common assumption that "the entire holding period gets calculated with one single logic straight through"?

Most people's intuitive way of calculating holding gain or loss treats the period from "acquisition date" to "disposition date" as one continuous, single-nature holding period, applying the same logic throughout (for example, cost basis stays fixed, gain calculated only once at the end). This intuition works fine in the straightforward scenario of "bought and left untouched until sold," but if you've actively bought more or sold part of the same batch of assets during the holding period, this assumption breaks down.

The problem Active-Passive Period Segmentation solves is recognizing that the same batch of assets' holding period can simultaneously include "transactions you actively decided on" (like adding to a position or partial selling) and "passive state changes the asset itself undergoes" (like a rebase mechanism automatically adjusting the balance, or exchange-rate accumulation) — two entirely different types of change that often follow different tax logic, and can't simply be run through with a single logic across the entire holding period.

Why does the holding period need to be split into segments — can't the gain/loss from active trades and passive changes just be totaled separately?

The reason this method needs "splitting into segments," rather than simply totaling gain or loss from active trades separately from that generated by passive changes, is fundamentally because the cost basis itself accumulates and changes over time — the conservative treatment logic during a passive-change period (like rebasing) typically rests on the question "has the proportional share changed," and the reference point for that judgment needs to be the cost basis and held quantity established by the most recent active trade, not the very first acquisition cost of the entire holding period.

Without segmentation, directly applying the original acquisition cost across the entire holding period (including subsequent active additions) leads to incorrect cost basis calculation — for example, the portion you actively bought mid-holding should have its cost basis set at the market price at the moment of that purchase, not the price from the original acquisition. Without segmentation, this later-added batch of assets could be incorrectly assigned the original old cost basis, causing the final calculated gain or loss to be completely distorted. Splitting into segments essentially ensures that the calculation within each period is based on the correct, independent cost basis starting point established at the beginning of that segment.

How does Active-Passive Period Segmentation actually work, and how do different scenarios differ?

There are three common scenarios:

1. A single active trade point: the entire holding period has only one active trade (for example, a single instance of buying more). The holding period gets split into two segments — the passive-holding segment before the addition, and the passive-holding segment after it — each applying the conservative treatment logic for passive changes, with cost basis re-established at the moment of the addition
2. Multiple active trade points: if the entire holding period has multiple active trades, the number of segments increases correspondingly — each active trade is a new dividing point, requiring you to clarify each segment's own starting cost basis and held quantity one by one
3. An active trade happening right at the same time as a passive-change event (for example, trading exactly when a rebase triggers a depeg event): this is the most complex scenario, requiring first confirming the taxable moment determination for the depeg event itself, then confirming whether your active trade happened before or after that taxable moment — the sequence of these two points in time affects which market price your active trade's cost basis should be calculated at

In practice, if your holding history involves multiple active trades, it's advisable to compile a complete timeline, clearly marking the date, quantity, and market price at the time of each active trade, along with the timing of each passive-change event (such as a rebase trigger point, or a depeg event) — this timeline is the foundation for correctly segmenting and calculating afterward.

What does Active-Passive Period Segmentation actually mean for me, and what risks should I watch for?

The most direct impact is that if you've ever made any active trade on the same batch of assets with passive-change characteristics (like rebase tokens or receipt tokens), even just once, you can't simply file using the simplified approach of "one logic calculated straight through the entire holding period" — you need to first clarify whether your holding history contains any active trade points before deciding whether segmentation is needed.

Another easily overlooked risk is that many people tend to overlook seemingly unimportant transactions like a "small addition" or "selling off a small portion," which actually still constitute an active trade point requiring segmentation — it isn't only large-amount transactions that count. Any single active buy or sell decision theoretically creates a new segment dividing point. In practice, it's advisable that as long as you hold the same batch of assets with passive-change characteristics, you build a habit of recording every active trade (regardless of amount), avoiding a situation where forgetting one small transaction later throws off the entire calculation.