Han Ozsoylev is Lecturer in Financial Economics at Saïd Business School, University of Oxford. His areas of expertise include asset pricing, market microstructure and information economics.

Ozsoylev’s research primarily focuses on financial market imperfections, such as those generated by asymmetric information, imperfect competition, and behavioural biases. Recently he has studied the role of networks in financial markets, focusing on information networks among securities market investors and trading and credit networks among financial institutions. He is also interested in questions related to ambiguity in markets, liquidity, and price manipulation. His research has been published in a range of academic journals including The Journal of Economic Theory and The Journal of Financial Markets.

Ozsoylev is an academic member of the Oxford-Man Institute of Quantitative Finance. He has held visiting appointments at Sabanci University’s School of Management, Johns Hopkins University’s Department of Economics and University of California, Berkeley’s Haas School of Business.

Before joining Saïd Business School in 2004, Ozsoylev earned a PhD in economics from the University of Minnesota, USA and a BSc in mathematics from Bilkent University, Turkey.

• Areas of expertise include:
  Asset pricing
  Financial networks
  Investor networks
  Liquidity
  Market efficiency
  Market microstructure
  Price manipulation

Ozsoylev conducts research on financial market imperfections, such as those generated by asymmetric information, imperfect competition, behavioural biases, and bounded memory.  He works both independently and collaboratively with colleagues from different institutions and backgrounds.

Networks in financial markets
The social and information networks through which communication in financial markets takes place are significant for financial investors’ decision-making processes. Ozsoylev’s research investigates how such networks affect asset prices and investor welfare.

He argues that profit distribution among investors and their trading volume are intimately linked to those investors’ centrality within the information network. Further, the network that optimizes total investor welfare is typically one with an intermediate degree of connectedness. Ozsoylev’s collaborative empirical research lends support to some of these theoretical findings.

Related publications:
Ozsoylev, H.N. and J. Walden (2011), Asset pricing in large information networks , Journal of Economic Theory, vol. 146, pp. 2252-2280.
Ozsoylev, H.N., J. Walden, D. Yavuz and R. Bildik, Investor networks in the stock market, AFA 2012 Chicago Meetings Paper.
Eren, N. And H.N. Ozsoylev, Communication dilemma in speculative markets, working paper.
Ozsoylev, H.N., Asset pricing implications of social networks, AFA 2006 Boston Meetings Paper.
Ozsoylev, H.N., Rational expectations and social interaction in financial markets, working paper.

Price manipulation
Stock market manipulation is an old yet effective game. One of the most well-known manipulation schemes is the ‘hype and dump’ manipulation, also referred to as ‘pump and dump’. This practice is illegal in many countries, yet it is common. Ozsoylev’s research shows that intense regulatory enforcement, which makes dishonest rumour-mongering very costly, may not necessarily curb hype and dump schemes. Market depth and trading volume rise with ‘hype and dump’ while market efficiency decreases.

Related publications:
Eren, N. and H.N. Ozsoylev, Hype and dump manipulation, AFA 2008 New Orleans Meetings Paper.

Ambiguity and market liquidity
The quality of information in financial markets is often hard to estimate. Investors may be unable to form a single probability belief about asset returns conditional on information signals, and act on the basis of ambiguous (or multiple) probability beliefs. Ozsoylev’s research shows that the presence of ambiguous information gives rise to the possibility of an illiquid market where uninformed investors optimally choose not to participate in trading. When the market is illiquid, small informational or supply shocks have relatively large effects on asset prices.

Related publications:
Ozsoylev, H.N. and J. Werner (2011), Liquidity and asset prices in rational expectations equilibrium with ambiguous information, Economic Theory, 2011, vol. 48, pp. 469-491.

Financial fragility and market microstructure
Ozsoylev’s research also explores questions related to basic microstructure theory and financial fragility.

Related publications:
Ozsoylev, H.N. and S. Takayama (2010), Price, trade size, and information revelation in multi-period securities markets, Journal of Financial Markets, 2010, vol. 13, pp. 49-76.
Ozsoylev, H.N. (2008), Amplification and asymmetry in crashes and frenzies,
Annals of Finance, 2008, vol. 4, pp. 157-181.

Ozsoylev teaches corporate valuation on the School’s MBA, EMBA, MSc in Financial Economics and executive education programmes. Central to the corporate valuation courses is a focus on how to make good investment decisions. While the courses primarily deal with the underlying mechanics of corporate valuation, they also teach students how to create (and how not to destroy) corporate value.

Ozsoylev describes his teaching style as ‘encouraging the participants to roll up their sleeves and dive into the numbers and financial reports for critical and creative evaluation and analysis.’ Conducting valuation analysis is necessary but not sufficient in Ozsoylev’s classes: all students are expected to be able to justify and defend their analysis. He regularly brings insights and experience from the corporate world into the classroom with presentations from visiting expert practitioners.

• Ozsoylev teaches valuation on the following programmes:
  MBA
  MSc in Financial Economics
  EMBA
  Diploma in Financial Strategy
  

Much of Ozsoylev’s work is of relevance to finance practitioners and informs their understanding of how markets operate. He has a strong track record of outreach and engagement. His recent presentations to investment professionals and financial regulators include the London Quant Group’s annual seminar and talks at the Federal Reserve Banks. He regularly gives research seminars at major research universities and at international meetings, conferences, and research institutes.

Ozsoylev is an academic member of the Oxford-Man Institute of Quantitative Finance. He is also an affiliate of the Economic Research Forum, a think-tank on economic policy in Turkey.