\`x^2+y_1+z_12^34\`
Advanced Search
Article Contents
Article Contents

Supply–demand symmetry

Abstract / Introduction Full Text(HTML) Figure(22) Related Papers Cited by
  • We study what properties a liquidity surface (LS) must possess when the supply and demand of a given market are in equilibrium. To formalize this concept, we first analyze foreign exchange markets, where symmetry between the buy and sell sides just amounts to the invariance of market impact with respect to a change of base currency. We speak in this case of supply–demand symmetry, and call the corresponding LS symmetrical. We then extend the idea to general securities, applying similar change of numeraire arguments. We give necessary and sufficient conditions for characterizing symmetrical LS's and we classify all possible solutions to these conditions, providing some stylized examples. Symmetrical LS's are interpreted as equilibria around which liquidity imbalances fluctuate. We show that market impact functions which are even with respect to order size – usually adopted by market impact models in the literature to represent bid–ask symmetry – are not symmetrical LS's and are always associated to an excess of supply; they are approximations of symmetrical LS's only in the limit of highly liquid regimes (no bid–ask spread, small orders, small market impact).

    Mathematics Subject Classification: 91B24, 91B26, 91G15, 91B05.

    Citation:

    \begin{equation} \\ \end{equation}
  • 加载中
  • Figure 1.  The market impact of an hypothetical currency pair, which is even when expressed in one currency (blue line) is not even when expressed in the opposite currency (red line)

    Figure 2.  Graphical interpretation of supply–demand symmetry. A regular LS is symmetrical if and only if the plot of $ y = L(x)/m $ is symmetrical with respect to $ y = -x $, concave, increasing and passing through the origin. The orange line is such an example. These curves are confined to stay in the white area of the plane. Two extreme cases exist: the green line, which represents a perfectly liquid market, where quotes at all sizes coincide with fair price, ($ m(s) = m $, $ \forall s\in\mathbb{R} $); and the red line, which is the most illiquid possible market, where there aren't any quotes either on the bid or on the ask side ($ m(s) = +\infty $ if $ s<0 $, $ m(s) = 0 $ if $ s>0 $)

    Figure 3.  Graphical interpretation of the conjugation relationship $ s \leftrightarrow \tilde{s} $

    Figure 4.  Illustration of Proposition 3.16. $ L_+ $ represents the bid wing of a LS. The plot compares the ask wing $ L_- $ obtained assuming that impact is even and the ask wing $ \widetilde{L}_+ $ assuming a symmetrical LS. The former, is always more liquid

    Figure 5.  A symmetrical Liquidation Operator $ L(s) $, in the case of exponentially decaying MSDC bids and no bid–offer spread. We set $ m = 1 $, as in all the following similar plots

    Figure 6.  In the top plot the MSDC and SDC of the example in Figure 5. In the bottom plot, the corresponding marginal and average impacts. In this example, quotes decay to zero on the bid wing and diverge to infinity at some finite ask size

    Figure 7.  A symmetrical Liquidation Operator $ L(s) $, in the case of exponentially decaying MSDC bids with finite bid-offer spread

    Figure 8.  In the top plot the MSDC and SDC of the example in Figure 7. In the bottom plot, the corresponding marginal and average impacts

    Figure 9.  An asymptotically linear symmetrical Liquidation Operator $ L(s) $ with zero bid-offer spread. The corresponding MSDC is asymptotically flat as illustrated in Figure 12

    Figure 10.  In the top plot the MSDC and SDC of the example in Figure 9. In the bottom plot, the corresponding marginal and average impacts. MSDC and SDC are asymptotically flat in this example. These plots, at small size scales, are close to even functions in the sense of equation (1)

    Figure 11.  An asymptotically linear symmetrical Liquidation Operator $ L(s) $ with finite bid-offer spread. The corresponding MSDC is asymptotically flat as illustrated in Figure 12

    Figure 12.  In the top plot the MSDC and SDC of the example in Figure 11. In the bottom plot, the corresponding marginal and average impacts

    Figure 13.  A symmetrical Liquidation Operator $ L(s) $ built in such a way to have linear ask MSDC and no bid-offer spread

    Figure 14.  In the top plot the MSDC and SDC of the example in Figure 13. Both the MSDC and the SDC are linear on the ask side. The bid side is clearly not linear

    Figure 15.  A symmetrical Liquidation Operator $ L(s) $ built in such a way to have linear ask MSDC and finite bid–offer spread

    Figure 16.  In the top plot the MSDC and SDC of the example in Figure 5. Both the MSDC and the SDC are linear on the ask side. The bid side is clearly not linear

    Figure 17.  A symmetrical Liquidation Operator $ L(s) $ in the case where there are four finite bid quotes and four symmetrical finite ask quotes. The corresponding MSDC is piecewise constant, as illustrated in Figure 18

    Figure 18.  In the top plot the MSDC and SDC of the example in Figure 17. In the bottom plot, the corresponding marginal and average impacts. The visualization of the symmetry relation between corresponding bid and ask quotes is all but intuitive. Symmetrically placed bid and ask quotes have size and price in correspondence with each others as described by Proposition 3.6

    Figure 19.  Another symmetrical Liquidation Operator $ L(s) $ with symmetrical finite bid and ask quotes. The example is made with finer quotes with a lesser degree of illiquidity, giving rise to a more regular pattern

    Figure 20.  In the top plot the MSDC and SDC of example in Figure 19. In the bottom plot, the corresponding marginal and average impacts. This example, as compared with the one in Figure 18, is made of a strip of finer quotes and gives rise to a more regular pattern, with a behavior at small size scales which is closer to an even function

    Figure 21.  In the top plot a symmetrical LS obtained from a power–law (square–root) MSDC on the bid side and no bid–offer spread. The marginal impact is shown in the bottom plot to display that for small degree of illiquidity and/or small size, impact can be approximated by an even function, as proved in Corollary 3.9

    Figure 22.  A similar example to the one in Figure 21 but with a finite bid–offer spread. The bottom plot shows impact as a difference from mid–price. It can be noticed that in this case, impact is not an even function even at small size scales, as described in Corollary 3.9

  • [1] C. Acerbi and Zs. Szekeres, Introduction to LiquidityMetrics, MSCI Technical Document, 2013.
    [2] A. AlfonsiA. Fruth and A. Schied, Optimal execution strategies in limit order books with general shape functions, Quant. Finance, 10 (2010), 143-157. 
    [3] R. Almgren and N. Chriss, Optimal execution of portfolio transactions, The Journal of Risk, 3 (2001), 5-39.  doi: 10.21314/JOR.2001.041.
    [4] R. Almgren, C. Thum, E. Hauptmann and H. Li, Equity market impact, Risk Magazine, 2005.
    [5] BARRA, Market Impact Model Handbook, 1997.
    [6] J.-P. Bouchaud, J. D. Farmer and F. Lillo, How markets slowly digest changes in supply and demand, working paper, available at "ssrn.com", 2008. doi: 10.2139/ssrn.1266681.
    [7] J.-P. Bouchaud, Y. Gefen, M. Potters and M. Wyart, Fluctuations and response in financial markets: The subtle nature of 'random' price changes, Quantitative Finance, 2004. doi: 10.2139/ssrn.507322.
    [8] J. Gatheral, No-dynamic-arbitrage and market impact, Quantitative Finance, 10 (2010), 749-759.  doi: 10.1080/14697680903373692.
    [9] E. Goursat, A course in mathematical analysis, Vol. I, Ginn and Company, (1904), 404-405. https://archive.org/details/dli.ernet.523782/page/404/mode/2up.
    [10] G. Huberman and W. Stanzl, Price manipulation and quasi-arbitrage, Econometrica, 72 (2004), 1247-1275.  doi: 10.1111/j.1468-0262.2004.00531.x.
    [11] J. L. Lagrange, Nouvelle méthode pour résoudre les équations littérales par le moyen des séries, Mémoires de l'Académie Royale des Sciences et Belles–Lettres de Berlin, 24 (1770), 251-326. 
    [12] A. Obizhaeva and J. Wang, Optimal trading strategy and supply-demand dynamics, Discussion Paper MIT Sloan School of Management, 2005.
  • 加载中
Open Access Under a Creative Commons license

Figures(22)

SHARE

Article Metrics

HTML views(1383) PDF downloads(256) Cited by(0)

Access History

Other Articles By Authors

Catalog

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return