Judul: The Effect of Financial Ratios on Capital Gains in the Four Largest Banks on the IHSG During the COVID-19 Period
Abstrak: Pandemi COVID-19 telah memengaruhi kinerja perdagangan saham di Indonesia, salah satu sektor yang paling terdampak yaitu perbankan. Indikator keuangan memiliki peran penting untuk memberikan gambaran mengenai kondisi dan kesehatan pasar. Penelitian ini bertujuan untuk mengetahui pengaruh rasio keuangan dan perbedaan pengaruh rasio keuangan terhadap Capital Gains perbankan empat terbesar di IHSG pada masa pandemi COVID-19. Pengumpulan data dilakukan melalui website perusahaan dan Bursa Efek Indonesia (BEI). Hasil dari penelitian ini yaitu Earning Per Share memiliki pengaruh positif dan tidak signifikan terhadap Capital Gain, sedangkan Capital Adequacy Ratio berpengaruh positif signifikan dan Return On Equity berpengaruh negatif signifikan terhadap Capital Gain. Kemudian EPS, ROE, dan CAR pada perbankan memiliki perbedaan signifikan dan Capital Gain perbankan tidak memiliki perbedaan signifikan. Lebih lanjut, saat membandingkan antar bank, terdapat perbedaan signifikan dalam EPS, CAR, dan ROE antara BCA dan BNI, serta antara BNI dan BRI, The COVID-19 pandemic has had a notable impact on the stock trading performance in Indonesia, particularly in the banking sector. Financial indicators play a crucial role in providing insights into the market and companies' financial health. This research aims to examine the influence of financial ratios and the differential effects of these ratios on the capital gains of the four largest banks listed in the IHSG index during the COVID-19 pandemic. Data for this study were collected from the companies' websites and the Indonesia Stock Exchange (IDX). The findings of this study indicate that Earnings Per Share have a positive but statistically insignificant effect on Capital Gain. On the other hand, the Capital Adequacy Ratio exhibits a significant positive effect, whereas Return On Equity demonstrates a significant negative effect on Capital Gain. Moreover, significant differences exist in EPS, CAR, and ROE between BCA and BNI, as well as between BNI and BRI, highlighting dissimilarities in these indicators among the banks
Keyword: Banking, Capital Gain, Financial Ratio

Judul: Institutional Investor Decisions in Crisis (Case: KBMI-4 bank)
Abstrak: The Covid-19 pandemic had a significant impact on the profitability and volatility of banking issuers' stock prices on the Indonesia Stock Exchange (BEI), particularly in 2020 and 2021. Using 720 observational data from institutional investors of Indonesia's four largest banks (known as KBMI-4), this research examines institutional investors' responses during the pandemic by focusing on their stock investment portfolios and taking into account relevant macroeconomic indicators, financial fundamentals, and stock performance that may influence their decision-making process. This study analyzes the behavior of KBMI-4 institutional investors with growth investing, value investing, and GARP investment styles, based on locations in Indonesia, Asia, and Non-Asia, in three observation phases: pre-pandemic (January 2019 to February 2020), pandemic (March 2020 to June 2021), and recovery (July 2021 to June 2022). Kruskal-Wallis test, Dunnett's Multiple Comparison Test, and panel data regression modeling were utilized. Only investors with high investment values (>IDR1,5 billion) exhibited investment dynamics, with investment values increasing from pre-pandemic levels. Concerning the investment style variants and investor location base, which are considered proxies for herding behavior and home bias, it was determined that they had no impact on the investment decisions of KBMI 4 bank institutional investors. Compared to the pre-pandemic, only non-Asian investors exhibited significant differences in investment value. This growth is attributable to this group's high investment potential. Based on KSEI data, of the total 7.49 million investors in the Indonesian capital market as of December 31 2021, only less than 1.0% came from countries outside Asia. Panel data modeling: Inflation rate, Loan at Risk (LAR) ratio, LAR coverage, Return on Equity (ROE), and loan growth (LON) have a statistically significant impact on the stock investments made by institutional investors in KBMI-4 banks. This identifies asset quality and profitability as two crucial considerations for investors during the pandemic-induced crisis. In addition, the model revealed six other variables had a significant relationship, but their coefficients did not match the direction of the relationship predicted by the hypothesis. These variables were the BI-7DRRR, Covid-19 cases, PPOP growth, Loan to Deposit Ratio (LDR), CASA ratio, and Price to Earnings Growth (PEG). In the context of optimizing institutional investor investment, these seven variables can strengthen the previous conclusion that, in the midst of a pandemic, investors are focusing on indicators that can provide an indication of the end of the pandemic and the enhancement of the fundamental performance of KBMI-4 bank. The findings of this study strengthen the behavioral finance reference in the context of institutional investors, who are less susceptible to behavioral biases and have distinct rationales compared to individual investors in general., Pandemi Covid-19 memberikan dampak signifikan bagi emiten perbankan berupa menurunnya profitabilitas serta volatilitas harga sahamnya di Bursa Efek Indonesia (BEI) khususnya di tahun 2020 dan 2021. Menggunakan 720 data amatan dari investor institusi empat bank terbesar di Indonesia (KBMI-4), penelitian ini bertujuan untuk mengungkapkan bagaimana pandemi direspon investor institusi dalam bentuk perubahan portofolio investasi sahamnya dan menganalisis indikator-indikator terkait ekonomi makro, kinerja keuangan, dan kinerja saham yang dapat mempengaruhi proses pengambilan keputusan. Untuk memenuhi tujuan tersebut, penelitian ini menganalisis perilaku investor institusi bank
Keyword: behavioral finance, covid-19, determinant factors, institutional investors, stock investment

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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