01 / ROLE BOUNDARY & RESEARCH PATH

ETF is useful here because it solves a portfolio problem, not because it promises the highest standalone return.

ETF 在这里有价值，是因为它解决组合问题，而不是因为它承诺最高单体收益。

🟦 Role Boundary / 角色边界

ETF is an accessible market: product data is public, execution is simple, and monthly rebalancing is realistic for personal capital. That accessibility is useful, but it also means the obvious alpha layer is crowded. A broad ETF rotation system cannot be assumed to beat every simple buy-and-hold benchmark just because it is quantitative.

ETF 市场足够容易接近：产品数据公开，交易执行简单，月频调仓也符合个人资金的维护能力。这个优势很重要，但也说明显而易见的 alpha 层不会轻松。一个宽基 ETF 轮动系统，不能因为“量化”两个字就默认优于简单买入持有。

The more realistic role is portfolio stabilization. Convertible bonds carry the main return engine, but they still face equity beta, credit-event pressure and deep drawdown windows. ETF can use a different asset structure — A-share beta, overseas equity, Treasury and Gold — to reduce simultaneous exposure and improve the combined capital path.

更现实的角色是组合稳定器。可转债承担主要收益来源，但仍然面对权益 beta、信用事件压力和较深回撤窗口。ETF 可以用另一套资产结构：A 股宽基、海外权益、国债和黄金，去降低同步暴露，改善组合资金曲线。

◼ Research Question / 研究问题

The first research question was deliberately modest: can a low-frequency ETF module reach a reasonable stabilizer profile, and can it improve a convertible-bond portfolio after costs, common-window comparison and cross-border premium checks?

最初的问题刻意保持克制：一个低频 ETF 模块能否达到稳定器应有的风险收益特征？在交易成本、共同窗口比较和跨境 ETF 折溢价过滤之后，它能否改善可转债组合？

🟦 Research Path / 研究路径

The work moved from broad rotation intuition toward a simpler stabilizer design. The important discipline was not to make ETF look exciting, but to stop when a more aggressive idea did not serve the stabilizer role.

这条研究线从“ETF 轮动可能有用”的直觉，逐步收敛到更简单的稳定器设计。关键纪律不是让 ETF 看起来刺激，而是在更进攻的想法不适合稳定器角色时，及时降级或归档。