——可转债周报20251215：拟合溢价率曲线形态变迁，关注结构差异-20251216

1. Report Industry Investment Rating No information provided regarding the industry investment rating. 2. Core Viewpoints of the Report - As of December 12, 2025, the convertible bond's 100 - yuan fitted premium rate has risen to 31.82%. With the valuation reaching historical highs and continuing to fluctuate, there are doubts about the applicability of past curve - fitting methods in the current high - price and high - valuation market. The algorithm for the fitted premium rate may need to be re - explored [1][10]. - The convexity of the fitted premium rate curve has increased. The right - shift of the parity indicates a structural difference in the convertible bond market. High - parity convertible bonds have relatively stable valuations, and as parity decreases, the valuation premium rises faster, causing the convexity of the curve to strengthen. The change in parity may lead to deviations in the calculated 100 - yuan premium rate [1][15]. - The distribution of the conversion premium rate is more extreme. The low - parity group has a steeper slope of premium rate increase, and the high - parity group's premium rate has nearly doubled compared to the end of 2024, while the medium - parity group shows relatively small fluctuations. This requires a change in the function form for curve fitting [2][17]. - When the parity is changing, the fitting interval should be widened, especially towards high - parity. The fitting function form may be adjusted to an exponential form, which can better reflect the premium rate distribution in the high - parity range and is suitable for some low - price and high - valuation samples. Considering the expected positive performance of the equity market in 2026, attention can be paid to such fitting method adjustments [2][3]. 3. Summary According to the Table of Contents 3.1 Fitted Premium Rate Curve Shape Changes, Pay Attention to Structural Differences - Valuation and Parity Changes: As of December 12, 2025, the convertible bond's 100 - yuan fitted premium rate has reached 31.82%, up 11.14 pct from the beginning of the year, at the 98.90% historical quantile since 2017. The high - parity proportion has increased, and the traditional curve - fitting method may not be applicable [10]. - Convexity of the Fitted Curve: Compared with the end of 2024, the parity has shifted to the right. High - parity convertible bonds have stable valuations, and as parity decreases, the valuation premium rises faster, strengthening the convexity of the curve. The change in parity may cause the model to deviate, resulting in inaccurate 100 - yuan premium rate calculations [15]. - Extreme Distribution of Premium Rate: The low - parity (70 - 90) group has a steeper premium rate increase slope, and the high - parity (110 - 130) group's premium rate has nearly doubled compared to the end of 2024. The medium - parity group has relatively small fluctuations. The traditional cubic inverse function is not suitable for the current market, so the function form needs to be changed [2][17]. - Consider Extreme Parity Values: The common 70 - 130 fitting interval is less applicable when the parity rises. An exponential function (Y = A×e^(-k(x - B))+C) can be considered for fitting, as it has advantages at both ends and can better reflect the market distribution [2][19]. 3.2 Market Review: Convertible Bonds Rose Slightly Weekly, Valuation Remained Basically Flat 3.2.1 Weekly Market Quotes: Convertible Bond Market Rose Slightly, Most Equity Sectors Pulled Back - Index Performance: Last week, most major stock indices rose. The Shanghai Composite Index fell 0.34%, the Shenzhen Component Index rose 0.84%, the ChiNext Index rose 2.74%, the SSE 50 Index fell 0.25%, the CSI 1000 Index rose 0.39%, and the CSI Convertible Bond Index rose 0.20% [26]. - Industry and Concept Performance: In the Shenwan primary industry index, most equity markets pulled back last week. Communication, national defense and military industry, electronics, machinery and equipment, and power equipment led the gains; household appliances, basic chemicals, textile and apparel, real estate, and steel led the losses. The convertible bond market had mixed performance, with building materials, national defense and military industry, communication, automobiles, and power equipment leading the gains, and food and beverage, media, basic chemicals, commercial retail, and coal leading the losses. Among popular concepts, some concepts rose and some fell [30][33]. 3.2.2 Valuation Performance: Premium Rates of Convertible Bonds of Most Ratings and Sizes Rose - Closing Price and Premium Rate: The weighted average closing price of convertible bonds was 132.26, down 0.01% from the previous Friday. The closing price of equity - biased convertible bonds was 194.10 yuan, up 2.02% from last Friday; the closing price of bond - biased convertible bonds was 119.15 yuan, down 0.34% from last Friday; the closing price of balanced convertible bonds was 128.77 yuan, down 0.10% from last Friday. The proportion of the 120 - 130 (including 130) interval in the closing price distribution increased significantly. The price median was 130.59 yuan, down 0.21% from the previous Friday. The 100 - yuan parity fitted conversion premium rate of the convertible bond market was 31.82%, down 0.01 pct from last Friday. In terms of ratings and sizes, the premium rates of most convertible bonds rose [35]. 3.3 Terms and Supply: 2 Convertible Bonds Announced Forced Redemption, Total Pending Issuance Scale About 125 Billion 3.3.1 Terms: Last Week, 2 Convertible Bonds Announced Forced Redemption, 3 Convertible Bonds' Boards Proposed Downward Revisions - Forced Redemption: As of December 12, Yingbo and Hugong convertible bonds announced early redemption; Bojun convertible bond announced no early redemption; Xiangfeng, Kaisheng, Jinzhong, Furong, and Bo 23 convertible bonds announced that they were expected to meet the forced redemption conditions [4][55]. - Downward Revision: Last week, Bengang, Jinlang Zhuan 02, and Hongchuan convertible bonds issued announcements of the board's proposal for a downward revision of the conversion price. No convertible bonds announced the results of the downward revision. 15 convertible bonds announced no downward revision, and 11 convertible bonds announced that they were expected to trigger a downward revision [4][55]. 3.3.2 Primary Market: Last Week, Tianzhun, Shenyu, and Aohong Convertible Bonds Were Issued, Total Pending Issuance Scale About 125 Billion - Issuance and Listing: Last week, Tianzhun, Shenyu, and Aohong convertible bonds were issued, with a total scale of 19.52 billion yuan. Maolai and Ruike convertible bonds were listed, with a scale of 15.63 billion yuan. Dingjie convertible bond was listed on December 15, with a scale of 8.28 billion yuan [5][58]. - Pending Issuance: Last week, there were no new board proposals. Three companies passed the shareholders' meeting, two passed the issuance review committee's approval, and one was newly approved by the CSRC, an increase of +0, +3, +0, +1 respectively compared to the same period last year. As of December 12, four listed companies obtained convertible bond issuance approvals, with a proposed issuance scale of 41.67 billion yuan. Eight listed companies passed the issuance review committee, with a total scale of 83.14 billion yuan [60][65].