正解: BCorrect: B
金利と既発債の価格は逆方向に動きます。新発債の利回りが上がると、低い利率の既発債は値下がりして利回りを揃えます。Interest rates and existing bond prices move in opposite directions. When new bonds pay more, older lower-coupon bonds must fall in price until their yields match.
債券価格と金利の逆相関は金融リテラシーの基礎です。年2%の利息を払う既発債を持っているとき、市場金利が4%に上がれば、誰も額面で2%の債券を買いません。価格が下がって実質的な利回りが4%に近づくまで調整されます。満期が長い債券ほど将来の利息を長期間低い水準で受け取ることになるため、価格の下落幅は大きくなります（デュレーションの概念）。選択肢Dは逆で、短期債は影響が小さいのが一般的です。2022年に米欧の中央銀行が急速に利上げした際、多くの債券ファンドや年金基金が評価損を計上したのはこの仕組みによるものです。2023年のシリコンバレー銀行の破綻も、保有していた長期債の含み損が引き金になりました。The inverse relationship between interest rates and bond prices is a foundation of financial literacy. If you hold a bond paying 2 percent and market rates rise to 4 percent, nobody will pay face value for your bond; its price must fall until its effective yield approaches 4 percent. Longer-maturity bonds fall further because their below-market coupons persist for more years, a sensitivity captured by the concept of duration. Choice D reverses this: short-term bonds are less affected. When central banks in the United States and Europe raised rates rapidly in 2022, many bond funds and pension portfolios recorded valuation losses for exactly this reason. The 2023 failure of Silicon Valley Bank was triggered by unrealized losses on long-dated bonds it held, showing that even professionals can underestimate this mechanism.
多くの個人は「債券は安全」という単純化を信じ、金利上昇局面で債券ファンドの価格が下がると驚きます。また、満期まで保有すれば額面で償還される個別債券と、常に時価評価される債券ファンドの違いも混同されがちです。Many individuals hold the simplification that bonds are always safe and are surprised when bond funds lose value as rates rise. People also confuse individual bonds, which repay face value at maturity if held, with bond funds, which are continuously marked to market and have no fixed maturity date.
債券を保有する目的（安定収入か、株式の下落時の緩衝材か）を明確にし、保有する債券のデュレーションが自分の投資期間と合っているか確認しましょう。金利の方向を予想するより、期間を分散させる方が現実的な対処です。Clarify why you hold bonds, whether for steady income or as a cushion when equities fall, and check that the duration of your bond holdings matches your time horizon. Rather than trying to predict the direction of rates, spreading maturities across a range of dates is a more realistic way to manage the risk.