ドル円アノマリー追記：データが暴く「公務員の給料」も刈り取られる日 前回の記事では、「毎月25日の給料日」を起点としたシステム的な円売り・ドル買いアノマリーについて解説しました。今回はさらに解像度を上げ、「毎月1日〜31日の日付別」でドル円の平均変化率（リターン）を可視化してみました。 使用したPythonコードは以下の通りです。 ‘’’Python import yfinance as yf import matplotlib.pyplot as plt import pandas as pd import seaborn as sns # 分析期間の設定 dateStart = "2015-01-01" dateEnd   = "2026-05-23" ticker = "JPY=X"   # ドル円 df = yf.download(     ticker,     start=dateStart,     end=dateEnd,     auto_adjust=False,     progress=False ) if isinstance(df.columns, pd.MultiIndex):     close = df["Close"][ticker].dropna() else:     close = df["Close"].dropna() daily_return = close.pct_change() * 100 analysis_df = pd.DataFrame({"Return": daily_return}) analysis_df.index = pd.to_datetime(analysis_df.index) analysis_df["Day_of_Month"] = analysis_df.index.day analysis_df = analysis_df[analysis_df.index.dayofweek < 5] pivot_table = analysis_df.groupby("Day_of_Month")["Return...

Visualizing Japan's Capital Flight: The "Payday Anomaly" in USD/JPY The Japanese Yen has been experiencing historic weakness. While many attribute this solely to interest rate differentials or government interventions, I suspected a more mechanical, structural force at play: the automated capital flight by Japanese retail investors. The Hypothesis: The Payday Effect In Japan, the 25th of the month is the standard payday for most corporate workers. Recently, due to inflation and the new tax-free investment program (NISA), a massive number of people have set up automated monthly purchases of foreign equity index funds (such as the S&P 500 or All-Country World Index). I hypothesized that this creates an automatic, system-wide "Sell JPY / Buy USD" order triggered every single month around payday. The Code To verify this, I wrote a Python script using yfinance and seaborn to map the average daily return of USD/JPY by the week and day of the month, covering data...

Observational Notes on Silver Paper Investment Trusts • There are few signs that the physical silver price itself is about to decline. (Industrial demand and physical scarcity remain intact.) • However, there appear to be structural risks in the silver paper market (investment trusts, certificate-based products). • Recently: • A clearly inexperienced retail crowd has begun flowing into silver investment trust forums. • Discussions are heavily focused on price levels and price increases . • There is almost no discussion of delivery conditions, emergency clauses, or redemption terms . → This suggests a growing misconception that paper price = value . • At the same time, there are visible signs that: • More experienced participants, and • People with strong risk-management awareness are quietly taking profits and reducing positions. • This behavior appears less like a bearish view on silver itself , and more like a deliberate move to distance them...

+AI & ROI How +AI Changes the Structure of Demand Discussions around AI often focus on productivity gains or cost reductions. However, a more important and less discussed effect of +AI lies in how it transforms the structure of ROI (Return on Investment) itself. The key insight is simple but powerful: +AI primarily reduces the denominator of ROI — the Investment. This structural shift has consequences far beyond efficiency gains. +AI Shrinks the Investment Side of ROI ROI is defined as: ROI = Return / Investment Most technological progress attempts to increase the Return . +AI, however, does something different: • It dramatically lowers initial costs • It reduces human labor requirements • It eliminates the need for large-scale upfront infrastructure in many domains As a result, projects that previously failed to meet ROI thresholds suddenly become viable. This is not optimization at the margin — it is a redefinition of who can participate . Lower Investment Does Not ...