Judul: Short Put Ladder Strategy in Bitcoin Hedging
Abstrak: Pada tahun 2008, Bitcoin diperkenalkan oleh sebuah entitas anonim dengan nama samaran “Satoshi Nakamoto”. Empat belas tahun kemudian, Bitcoin telah menjadi cryptocurrency dengan kapitalisasi pasar terbesar. Hal ini menyebabkan tingkat volatilitas Bitcoin menjadi tinggi. Hedging dengan opsi put Eropa menggunakan strategi short put ladder (SPL) dapat melindungi nilai portofolio Bitcoin terhadap sifat Bitcoin yang volatil. Penelitian ini menganalisis keuntungan dan kerugian dari aksi hedging tersebut, lengkap dengan dua aksi awal hedger (long asset dan short asset) yang masing-masing disimulasikan dengan sepuluh skenario SPL yang berbeda-beda. Menggunakan model Black-Scholes-Merton untuk menentukan premi opsi put Eropa, penelitian ini mengevaluasi skenario terbaik dalam melindungi nilai portofolio. SPL dengan long asset memberi perlindungan kerugian saat bearish. SPL dengan short asset menghasilkan keuntungan saat bearish. Skenario terbaik dari SPL dengan long asset dihasilkan ketika strike price pertama jauh lebih kecil dari strike price kedua, serta strike price ketiga jauh lebih besar dari strike price kedua. Skenario terbaik dari SPL dengan short asset dihasilkan ketika strike price pertama dan strike price ketiga mendekati strike price kedua., In 2008, Bitcoin was introduced by an anonymous entity under the pseudonym “Satoshi Nakamoto”. Fourteen years later, Bitcoin has become a cryptocurrency with the largest market capitalization. This caused the volatility rate of Bitcoin to be high. Hedging with European put options using a short put ladder (SPL) strategy can protect the value of a Bitcoin portfolio against the volatile nature of Bitcoin. This study analyzes the profit and loss of the hedging action, complete with the two initial hedger actions (long asset and short asset), each simulated with ten different SPL scenarios. Using the Black-Scholes-Merton model to determine the premium of European put options, this study evaluates the best scenario for portfolio hedging. SPL with a long asset provides loss protection when bearish. SPL with a short asset turn profits when bearish. The best scenario of an SPL with a long asset is generated when the first strike price is much smaller than the second strike price, and the third strike price is much greater than the second strike price. The best scenario of an SPL with a short asset is generated when the first and the third strike prices are close to the second strike price.
Keyword: Black-Scholes-Merton, Bitcoin, lindung nilai, opsi, short put ladder

Judul: . Comparison of Inverse Vertical Ratio Put and Long
Strangle Strategies for Stock Price Hedging
Abstrak: Bukalapak merupakan salah satu perusahaan e-commerce yang terkena dampak positif perkembangan teknologi dan COVID-19. Persaingan antarplatform yang semakin beragam memungkinkan investor mengalami kerugian. Salah satu solusi untuk mengurangi risiko kerugian adalah lindung nilai dengan produk derivatif. Strategi inverse vertical ratio put adalah strategi perdagangan opsi yang melibatkan kombinasi penjualan dan pembelian opsi put dengan harga kesepakatan yang berbeda. Sedangkan, strategi long strangle melibatkan pembelian opsi put dan opsi call dengan harga pelaksanaan yang berbeda. Berdasarkan penilitian ini, kedua strategi ini sama-sama memberikan perlindungan ketika harga saham menurun dan memberikan profit portofolio dengan lindung nilai yang lebih baik ketika pasar tumbuh dibandingkan dengan posisi tanpa lindung nilai. Strategi inverse vertical ratio put cocok digunakan oleh investor ketika pergerakan harga saham di pasar sedang kondisi bearish dan strategi long strangle digunakan ketika terjadi pergerakan harga saham yang besar, baik harga saham bearish maupun bullish. Strategi long strangle lebih menguntungkan karena memberikan perlindungan terbaik ketika harga saham bearish sekaligus memberikan harga yang lebih baik ketika harga saham bullish., Bukalapak is one of the e-commerce companies positively affected by technological developments and COVID-19. The increasingly diverse inter-platform competition allows investors to experience losses. One solution to reduce the risk of loss is hedging with derivative products. Inverse vertical ratio put strategy is a type of options trading strategy that combines selling and buying put options with different strike prices. Meanwhile, the long strangle strategy involves buying put options and call options with different exercise prices. Based on this research, these two strategies provide protection when the stock price declines and better hedged portfolio profits when the market grows compared to unhedged positions. The inverse vertical ratio put strategy is suitable for investors when the stock price movement in the market is bearish, and the long strangle strategy is used when there is a large stock price movement, both bearish and bullish stock prices. The long strangle strategy is more profitable because it provides the best protection when the stock price is bearish while providing a better price when it is bullish.
Keyword: hedging, E-commerce, Inverse Vertical Ratio Put, Long Strangle, Bukalapak, Stock Portfolio

Judul: Bioecology of Earthworm Pheretima darnleiensis
Abstrak: Pheretima darnleiensis is a native earthworm in Southeast Asia, India, Japan, and Indonesia, however there is lack of study on P. darnleiensis. Determining the characteristics of P. darnleiensis and the ecology surrounding its habitat is needed in order to culture the earthworm. Hence, this study was aimed to study the structure of several organs and morphological characters that can be used to identify P. darnleiensis and its habitat condition. Earthworms were collected in a plot of 100 x 100 x 20 cm in 10 locations and were identified. The structure of P. darnleiensis organs was studied histologically using paraffin. Pheretima darnleiensis did not have diverticula and stalked gland on copulatory pouches, nephridia occurred on bithecate spermatheca, and the first spermathecal pores were at segment 4/5. Based on this study, the highest population of P. darnleiensis was found in an area containing abundance of other earthworm species at 15 individuals/m2, plant cover at 25.00%, soil arthropods at 16.32 individuals/kg fresh soil, abiotic component cover at 78.50%, soil temperature at 27.42 ± 1.01 oC, soil pH at 5.77 ± 0.53, soil moisture at 19.83 ± 9.92%, organic carbon at 3.39%, N at 0.29%, P at 286.80 ppm, K at 500.00 ppm, sand at 28.76%, silt at 38.74%, and clay at 32.50%. Silt fraction could be considered as one of factors influencing P. darnleiensis abundance.
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