Holter monitors are small, battery-powered medical devices that record the activities of the heart such as rate and rhythm. The Holter monitor was first developed at the Holter research laboratory in Helena Montana by experimental physicists Norman J. Holter and Bill Glasscock, who initiated work on radio telemetry in 1949. In the early 1950s, inspired by a suggestion from cardiologist Paul Dudley White, efforts were shifted toward the development of a wearable cardiac monitoring device. The Holter monitor was first commercially released in 1962. Since their inception, these devices have been a cornerstone for diagnosing suspected arrhythmias in patients across age groups. Conventional Holter monitors allow continuous registration of three or more leads for 24–48 hours. Latest generation Holter monitors allow continuous electrocardiogram (ECG) registration from 14 days to 60 days. Such prolonged monitoring with Holter monitors will increase the diagnostic yield of devices, especially for rhythm disturbances, which are infrequent yet recurrent.

Atrial fibrillation, also called AFib or AF, is an irregular and often rapid heart rate that can increase the risk of strokes, heart failure (HF) and other heart-related complications. During AF, the heart’s two upper chambers (the atria) beat chaotically and irregularly without proper coordination with the two lower chambers (the ventricles) of the heart. In AF, the irregular heartbeat results in ineffective blood circulation out of the heart and through the body. This causes blood collecting, or pooling, in the heart where clots can form. In case a clot travels to the brain, a stroke can occur. People with AF are at 5-7 times higher risk of a stroke than the general population.

21年至今，半导体（SW）行业指数涨幅为-0.48%，同期电子（SW）行业指数-2.07%，沪深300指数+2.41%，而海外费城半导体/台湾半导体指数为7.74%/15.99%，国内半导体指数明显跑输海外。细分产业链中，国内个别设计龙头相对表现较佳，设备、材料跌幅较大，而海外封测、设备、IDM及存储等涨幅较大，设计相对跑输，海外产业链中上游表现更佳，与景气度趋势更相关。

国信电子观点低估值高成长的二线龙头投资机会凸显。随着主力抱团板块的估值和市值规模进入新高，我们认为市场资金将会重视低估值高成长的灵活性标的投资机会。横向比较电子行业各大板块，我们认为被动元器件板块符合此类投资风格，建议关注具备长线逻辑的优质龙头公司如顺络电子，风华高科，三环集团，法拉电子、洁美科技等。

2019 年PCB 及上游CCL 是我们重点推荐的5G 投资主线之一，背后驱动是5G 拉动的新一轮通信基建，通信PCB 龙头标的业绩和估值双击；同时由于材料向高频高速升级，本土覆铜板龙头有望抢占海外供应商份额，随着认证和扩产的推进，相关标的估值提升。

投资建议：维持行业评级“同步大市-A”，行业进入Q1 季末，年报逐步披露，21Q1 业绩也逐渐浮出水面，基本面或成为主要的关注点，但宏观经济层面风险仍然存在，建议保持谨慎。

从去年下半年开始，芯片整体产能处于持续紧张状态，其中8 寸晶圆尤甚，近期甚至因为缺货导致整车厂生产进度受到影响。欧美整车大厂也主动和晶圆厂沟通，希望能够增加产能缓解产能问题。以台积电为例，车规级MCU 是在28/40nm 制程完成，主要客户包括NXP、瑞萨、TI 和英飞凌，近期有望得到更多的产能支持缓解产能瓶颈。