This paper focuses on if common effective spread estimators are appropriate for the proxy of Taiwan Futures Exchange. I use public available time and sales data, apply three methods, Roll’s (1984), Thompson and Waller’s (1988), and Smith and Whaley’s (1994) to assess effective spread, and then, compare them with the measured transaction costs proposed by Demsetz (1968). My results indicate that the latter two estimators not only are highly correlated with true transaction costs, but also provide good estimates, while Roll’s estimator appears to be inappropriate applied.

中文摘要 對於資本市場來說是外國公司的買賣價差的三個成分：逆選擇成分、交易成本成分及存貨成本成分相對於本國公司的買賣價差三成分構成有可能不同。 此篇論文中比較相同股票在不同市場所發行股票，其買賣價差三成分。根據本篇實證結果，相同一支股票在美國NYSE或是NASDAQ的逆選擇成分顯著的高於在TSEC發行的逆選擇成分，這暗指著資本市場中有很多不一樣的地方值得探討，像是流通貨幣的不同、或是法規治令的不同以及取得非公開資訊的難易程度也不同。另外，根據之前的研究的顯示，買單接著買單、賣單接著賣單的機率趨勢也很強，我們也發現了這種現象在TSEC很明顯，根據此篇論文的結論，這大部分的原因很可能是因為TSEC有「限價」規定的緣故。 / Abstract The three components, adverse selection component, order processing component and inventory holding cost, of companies which regarded as foreign companies in terms of the capital market are different from those in domestic capital market. In this paper, the adverse selection components of the stocks we choose in NYSE or NASDAQ are significant higher than those in TSEC. It implies the differences of capital markets, such as currency ,regulation and easy or not obtaining the private information of the company. Furthermore, similar to previous studies, there are strong tendencies for buys follow buys and sells follow sells. We find that the most part of proportion of order persistence derives from price limit in TSEC.

本研究的研究主題是探討影響台灣投資人使用限價單投資策略的影響因素為何。與歷史文獻不同的是，本研究直接以限價單量的變化來作為應變數，且使用８６年台灣證券交易所之市場微資料中之台灣積體電路之資料作為實證來源。 根據文獻間接指出，影響投資人之獲利狀況而可能導致其偏好使用限價單的影響因素有買賣價差之大小，成交量之多寡，投資人士是否具有資訊，與股價波動率大小等等。而根據本研究之實證顯示，限價單量之變化隨著委託時間而呈現遞減的現象，尤其在開盤前的三十分鐘之內達到最大。且本研究發現資料顯示一月份的限價單量相對較大，這可能是由於當年一月份之成交量相對較低的緣故。 至於影響投資人使用限價單之因素方面，實證顯示買賣價差，成交量之大小以及股價波動率與限價單的變化關係密切，且在本研究的模型中，對於限價單量之變化之解釋力高達６０%。而在第二部分之實證中顯示，市場上幾乎有90%的限價單量來自散戶，但法人（不包含自營商）的下單行為中卻以限價單居多。不論是法人或散戶皆有出現限價單量隨委託時間而遞減的狀況，而一月份限價單量較多的現象再法人中卻不明顯。 最後，本研究之模型可解釋散戶限價單量變化之情形，但是對於法人之限價單量變化之解釋力卻非常低，這或許是由於法人受到法規的限制無法完全以獲利大小出發點來進行下單行為。

This paper investigates the liquidity and the bid-ask spread components of the Taiwan Stock Exchange Capitalization Weighted Stock Index futures contracts, Taiwan Stock Exchange Electronic Sector Index futures contracts, and Taiwan Stock Exchange Banking and Insurance Sector Index futures contracts traded on the Taiwan Futures Exchange, which switched from an electronic periodic call auction market to an electronic continuous auction market on July 29th 2002. It is a rare opportunity to deeply examine the liquidity and transaction cost components of financial derivatives under different trading mechanisms. Using intraday transaction data of transaction and quotes covering from March 2002 to May 2002 for the old trading mechanism and from October 2002 to December 2002 for the new trading mechanism, liquidity measures and bid-ask spread components are examined before and after the enforcement of the electronic continuous auction mechanism. First, for each type of futures contracts, liquidity measures including bid-ask spread, trading volume, trade number, trade size, volatility, and liquidity ratio are explored to show the multifacet of liquidity. Next, the model of Lin, Sanger, and Booth (1995) is used to decompose the spreads of each product in the two periods. The empirical results show that quote spreads, effective spreads, percentage effective spreads, and dollar-weighted percentage effective spreads of the new system are all significantly lower than those measures in the old system for all of the three types of futures contracts. However, other liquidity measures do not show the same patterns. Overall, improvement of liquidity is found for futures contracts but not very consistent though. Multifacet of liquidity is showed by different measures, although two of these measures, including trade size and trade number, may not be suitable for this study. Moreover, the adverse selection is the most important component in the call auction market, which decreases in the continuous auction market. However, the change of other components, including order processing cost and order persistence, does not demonstrate the same pattern. The results indicate that the electronic continuous auction system protects uninformed traders from being hurt by informed traders. However, we also show that each type of futures contracts has its own specific component structure.

投資型商品連動於特定資產，保險人除了面臨原有的核保風險，更需承擔部分的財務風險。傳統保險商品的純保費價格等於其預期損失，而投資型商品的保險給付依據投資標的波動，保險人的預期損失不易估算，傳統精算的評價方法不完全適用於投資型商品。保證最低給付的給付結構使得投資型商品其有選擇權的特質，Brennan與Schwartz(1976)首先利用選擇權定價理論探討附有保證最低給付投資型商品之價值與避險策略，爾後亦有許多文獻以此方向加以著墨，但選擇權定價理論是基於市場為完全市場的假設，保險市場為不完全市場，以完全市場假設之理論評定保險商品之價值實不合理。本為假設保險人面臨的風險為核保風險及財務風險，財務市場為完全市場，保險人可以藉由市場上的各種金融商品建構避險組合規避財務風險；而預期死亡人數與實際死亡人數所產生的核保誤差，保險人無法利用避險組合完全地規避，因此保險市場為不完全市場。 在不完全市場中請求權的價值牽涉投資者主觀的風險偏好，不存在唯一的平賭測度，請求權的價格也不唯一，最適避險策略依請求權的價格調整，所以投資型保險商品的價格不再等於其公平價值，真正的成交價格應落於買賣價差之中。本文引用Mercurio(1996)的結果，利用二次效用函數，以極大化保險人期末財富之效用為目標，建構生存險的合理價格範圍。以二元樹模型描述股票的波動，分別模擬五年、十年及十五年投資型生存險之價差範圍，保險人的風險規避程度、保單期限以及保證金額的高低將影響商品價差範圍的大小。 關鍵字：不完全市場、效用函數，買賣價差、最適避險策略 / Investment-linked life (LIL) insurance policies integrate the attributes from the mutual fund by introducing the investment options to the policyholders and life insurance through the benefit payments shielding the unexpected events of the insured. Since the execution of the implied options depends on the policyholder's health status. Actuarial equivalent principal and non-arbitrage pricing theory are used in evaluating the prices for LIL insurance policies. Brennan and Schwartz (1976) initially employ the option pricing theory in examining the pricing and hedging strategy for LIL insurance policies with minimum guarantees. Most published literatures are focusing on this issue adopting the B-S methodology. Since the values of the LIL policies cannot be replicated uniquely through the self-financing strategies due to underwriting risks of the insurance market. Insurance market does not satisfy the completeness assumptions, Due to lack of a unique martingale measure under market incompleteness, the utility assumption of the policyholder is involved in the pricing issue. Insurance pricing must consider the risk attitude of the investors in the market. Hence the cost the LIL insurance policies are not necessarily equal to the fair market prices. The market value should fall within the range of the bid and ask prices. In this study, we follow the approach in Mercurio (1996) by adopting the quadratic utility function and compute the reasonable range of the prices based on maximizing the terminal health utility function. Binary tree method is used in modeling the asset dynamics. Then the numerical computations are performed using endowment LIL insurance policies with 5, 10 and 15 years of duration. Based on the results, we find that the risk attitude of the policyholder, the policy duration and minimum amounts of the guarantees significantly affect the bid-ask price spread of LIL insurance policies. Keywords: market incompleteness; utility function; bid-ask spread; optimal hedging strategy.

本篇論文基於市場上所存在的一些交易機制，探討漲跌停前後之股價行為。因為證券市場上存在一些交易規則，例如漲跌停限制、買賣價差、最小升降單位限制、競價制度等，這些交易規則，具有法定的效力，理所當然地會影響投資人的行為。這種以各種交易機制的存在，探討價格形成的過程，就是市場微結構理論之研究範疇。 本篇引用Hausman, Lo, and MacKinlay (1992)所建立之Ordered Probit模型來分析漲跌停前後之股價行為，以個股逐筆交易的價格變動為因變數，而建立因變數為間斷型之分析模型，並以等待撮合時間、交易量、落後期交易價格、買賣價差等經濟變數，來探討個股逐筆交易價格變動的成因。在此同時，鑑於以往研究多假定價量關係為線性，本研究引入非線性的概念，檢定價量之間是否存有非線線性之關係；最後，為使模型更具解釋力，我們引入異質性變異數。 第一章 緒論……………………………………………………………..1 第一節 研究動機……………………………………………..1 第二節 研究目的……………………………………………..7 第三節 研究範圍與限制……………………………………..7 第四節 研究架構與內容……………………………………..8 第二章 文獻回顧……………………………………………………….10 第一節 非同時交易………………………………………….10 第二節 最小升降單位……………………………………….11 第三節 買賣價差…………………………………………….14 第四節 漲跌停限制………………………………………….15 第五節 重要模型回顧…………………………………….…18 2.5.1 Chou(1996)……………………………………..18 2.5.2 Hausman, Lo, and MacKinlay(1992)…………..20 第三章 實證模型設定………………………………………………….25 第一節 資料來源…………………………………………….25 第二節 樣本選取…………………………………………….25 第三節 模型設定…………………………………………….26 3.3.1 價格的變動區間……………………………….26 3.3.2 解釋變數……………………………………….29 3.3.3 條件變異數的型式…………………………….32 3.3.4 價格與成交量之間非線性關係的檢定……….32 第四節 資料處理…………………………………………….33 第四章 實證分析……………………………………………………….36 第一節 模型基本統計分析………………………………….36 第二節 價量非線性關係的檢定…………………………….39 第三節 Ordered Probit模型實證分析……………………….40 第五章 結論與建議……………………………………………………..48 第一節 結論…………………………………………………..48 第二節 建議…………………………………………………..49 參考文獻…………………………………………………………………..50 / This thesis is an application of the market microstructure theory’. In light of some trading mechanisms in our stock market, such as price limit, bid-asked spread, tick size, and auction system, those trading rules would influence the behavior of investors. We want to study the process and outcomes of stock price under those explicit trading rules. We use the Ordered Probit model (Hausman, Lo, and MacKinlay, 1992) to investigate the stock behaviors when it hits price limits. We also use price change as the discrete dependent variable, and time elapsed, trading volume, lag price changes, bid-asked spread as explanatory variables. In order to make the model more explainable, heterogeneity is applied. Moreover, we also want to find out if there is any nonlinear relationship between price change and trading volume.

我國金融市場積極發展多元化與國際化，將由台灣期貨交易所推出臺指選擇權，建立選擇權市場以完備金融市場。由於選擇權市場掛牌交易契約眾多與選擇權的交易特性，因此有賴造市者發揮提供流動性、風險移轉、價格效率性及價格資訊揭露等經濟功能。本研究以造市者之功能性逐項比較我國造市者制度與EUREX、SEHK、LIFFE等各大交易所造市者制度之差異，用以發現我國首度引進的造市者制度對於選擇權市場發展的影響。 本研究為瞭解選擇權造市者營運的知識與技術，整理造市者作業循環的流程，針對造市者業務進行分工，建立起造市風險分析架構。推導得出造市風險包含造市交易風險與部位管理風險，呈現出市場波性風險、報價及交易策略風險、造市交易之市場機制風險、市場行情變動風險、遇險交易策略風險、部位管理之市場機制風險及財務與作業風險等七大類的造市風險。 本研究亦提出對於我國選擇權市場未來發展方向的關切，以及建議重視造市者利基與市場運作之關係，並提出未來與造市者相關之研究建議。 / Taiwan's financial market has been developing constructively into a globalization and multiplicity market within these years. To create a more completed financial market, Taiwan Futures Exchange (TAIFEX) will issue "the Taiwan stock index option" recently. As the complex and various features of the options trading, the option market will be successful and efficient through the market maker's economic functions, which are adding liquidity, increasing price efficiency, transferring risk and proving price information. This survey tried to compare the different functions of market maker system with TAIFEX, EUREX, SEHK and LEFFE, and to disclose the influence of the new market maker system on Taiwan's option market. This exposure takes great interest in market maker's knowledge and technology. By summarizing and classifying the operation process cycle flow of market maker, this research further organizes an analytic structure in market maker's risks. Including the market making risks and the positions management risks, the discussion demonstrates the market change risk, pricing strategy risk, limitary quoting risk, market volatility risk, hedging risk, mechanism risk, and finance and operation risk. The consequent also furnishes the concerns about the future development of Taiwan option market, emphasizing the importance of the relationship between market makers and market' benefit, and the suggestions to the further research.