The emergence of the COVID-19 pandemic, a new and novel risk factor, leads to the stock price crash due to the investors’ rapid and synchronous sell-off. However, within a short period, the quality sectors start recovering from the bottom. A stock price model has been developed to capture the price dynamics during shock and recovery phases of such crisis. The main variable and parameter of the model are the net fund flow (${\mathrm{\Psi }}_t$) due to institutional investors, and financial antifragility ($\varphi$) of a company, respectively. We assume that during the crash, the stock price fall is independent of the $\varphi$. We study the effects of shock length (${\mathcal{T}}_S$) and $\varphi$ on the stock price during the crisis period using the ${\mathrm{\Psi }}_t$ obtained from both the synthetic fund flow data and real fund flow data. We observed that the possibility of recovery of stock with $\varphi >0$, termed as quality stock, decreases with an increase in ${\mathcal{T}}_S$ beyond a specific period. A quality stock with higher $\varphi$ shows V-shape recovery and outperform others. The ${\mathcal{T}}_S$ and recovery period of quality stock are almost equal in the Indian market. Financially stressed stocks, i.e., the stocks with $\varphi <0$, show L-shape recovery during the pandemic. The stock data and model analysis show that the investors, in the uncertainty like COVID-19, invest in the quality stocks to restructure their portfolio to reduce the risk. The study may help the investors to make the right investment decision during a crisis.

COVID-19 大流行病的出现是一种新的风险因素，由于投资者的快速同步抛售导致股价暴跌。但短期内，优质板块开始触底回升。已经开发了一个股票价格模型来捕捉这种危机的冲击和恢复阶段的价格动态。模型的主要变量和参数是净资金流量（${\mathrm{\psi }}_{吨}$) 由于机构投资者和金融反脆弱性 ($\phi$) 分别属于一家公司。我们假设在崩盘期间，股价下跌独立于$\phi$. 我们研究冲击长度的影响（${\mathcal{吨}}_{\mathrm{小号}}$） 和$\phi$在危机期间使用股票价格${\mathrm{\psi }}_{吨}$从综合资金流量数据和真实资金流量数据中获得。我们观察到库存恢复的可能性$\phi >0$，称为优质库存，随着库存的增加而减少${\mathcal{吨}}_{\mathrm{小号}}$超出特定时期。优质股票$\phi$显示 V 型恢复并优于其他人。这${\mathcal{吨}}_{\mathrm{小号}}$和优质库存的回收期在印度市场几乎相当。财务压力大的股票，即具有$\phi <0$, 显示大流行期间的 L 形恢复。股票数据和模型分析表明，投资者在像 COVID-19 这样的不确定性中，投资于优质股票以重组其投资组合以降低风险。该研究可能有助于投资者在危机期间做出正确的投资决策。