JBMA Rolling Returns

Over 15 years, JBM Auto Ltd. has been through 61 separate 15 years holding periods — one starting every month. The median returned 44.6% a year, the worst 34.7% and the best 59.9%. A rolling return measures every possible start date instead of one, which is why it answers a question a single headline CAGR cannot: how much the outcome depended on when you happened to buy.

No — not in any of the 121 10 years periods the record covers. The weakest of them still compounded at 25.8% a year. That is a statement about the past, not a guarantee about any future 10 years, and it is measured only over the years JBM Auto Ltd. has been listed.

-7.6% a year, for the five years beginning March 2015. For contrast the best 5 years returned 106.7% a year, starting October 2012, and the median across all 181 periods was 51.4%. The gap between those two numbers is the part of the outcome that came down to timing rather than to the company.

On this record, yes. 1 year outcomes ranged from -66.0% to 1935.7% a year — a spread of 2001.7%. 15 years outcomes ranged from 34.7% to 59.9%, a spread of 25.1%. Longer holding periods narrowed the range of results, which is the usual pattern and the reason this page publishes every window rather than one. Narrowing the range is not the same as removing the risk.

In 100.0% of the 61 15 years periods both series cover. Each window is compared against the index over the identical months, not against an assumed index return, so the comparison is a like-for-like record rather than a model.

Windows step forward one month at a time on month-end closing prices adjusted for dividends and stock splits, so dividends are treated as reinvested. A window length is only published once there are at least twelve complete windows behind it — fewer than that describes an anecdote, not a distribution. Overlapping windows share months by construction, which is what makes this a description of the actual history of JBM Auto Ltd. rather than a sample of independent trials. Companies that delisted are not on this site at all, a survivorship bias worth holding in mind.

That is not a question this page answers, and we do not make recommendations. What it can show you is the full range of what every holding period in the listed history of JBM Auto Ltd. actually produced — including the worst ones, which most performance figures leave out. Those are records of what happened, not forecasts. A stock that never had a losing decade may still have one, and holding a single company is a materially different risk from holding an index.