9 Rivers Country Club is a free seasonality tracker and an ECHO / SPCX proxy calculator. The name is a nod to the golf club in King of the Hill; the numbers are built from Yahoo Finance daily closes, SEC filings and one FRED series, nothing else. No account, no tracking pixels, no newsletter.
Each week of the year (Sunday-start, Jan 1 = week 1, week 53 dropped) is summarised by its average daily close. The weekly variation is that average against the previous week's average. The N Year Avg Performance line is the mean weekly variation per week number over every week that started on or after today minus N + 1 years (N full years plus the current one), drawn cumulatively on the right axis. YTD Performance is this year's weekly average close, a price, on the left axis.
A month's return is its last close against the previous month's last close (the current month is month to date). N Year Avg is the mean per calendar month over the same window; This Year is this year's monthly returns; Last 5 years is the mean over the last five complete calendar years. Longer windows average over more regimes: the tooltip and the table show how many years each month or week has behind it.
The Year control shows the page as it stood at the end of a past year: prices are cut at December 31, that year's weekly and monthly series take the place of this year's, and the lookback window ends there (N full years plus the year itself, the same rule the live page applies to the current year). Back to 1928 for the S&P 500; as far as Yahoo's history goes for the rest.
We tested it. Each year in a window was scored against the map built from the other years (Spearman rank correlation, leave-one-out) and the scores averaged with a t-statistic across years. At the default ten-year window, as of October 2026, nothing in the universe beat chance: the S&P 500's monthly score was +0.13 (t 2.0) and its weekly −0.06, and the Nasdaq 100's weekly map ran against the years that built it. Over the S&P 500's 99 years the monthly map scores +0.10 (t 3.6) and the weekly +0.06 (t 5.1), with 58 to 70% of years positive. That is the honest reading of seasonality: a mild tendency over very long samples, noise over the windows most charts use.
Prices are Yahoo Finance daily closes, auto-adjusted, the full history per ticker, cached 180 minutes. Yahoo's history is shorter for some futures and FX pairs than for the indices; the page states where each window really starts. Index symbols are the cash index, futures symbols are the front contract Yahoo continuous series. Any Yahoo ticker works, including single stocks, but a name with a few years of history gives a map with a few observations per month: read the counts.
The method mirrors the Annual Seasonality and Monthly Seasonality pages of a well-known retail research tool, read from its own component definitions on 2026-10-20 and checked on SPX500: the monthly figures matched to four decimals, the weekly this-year averages to the cent, the ten-year weekly means correlated 0.95.
EchoStar sold spectrum to SpaceX for $19.6B, paid mostly in SpaceX stock that is delivered at a second closing targeted for November 30, 2027. The calculator builds EchoStar's net asset value at that closing from its filings (the ~261.8M SPCX shares at the price you pick, management's cash and wind-down guides, the cash left after SpaceX pays off the secured notes, the tax on the gain under three views, the operating assets and the remaining spectrum), weights in a deal-break case, applies the multiple of NAV you expect ECHO to trade at with the shares in hand, and discounts it back at the return you need for waiting. Every input carries its filing citation on the page; the model itself is served as plain JavaScript.
Not financial advice. Nothing here is a recommendation to buy or sell anything. Past seasonality does not predict future returns.