Firm characteristics help estimate conditional factor loadings. Larger libraries contain new and overlapping information. We use the cross-sectional distribution of firm characteristics as a ruler to evaluate IPCA loading spaces. With factor counts fixed, expanding from 36 to 153 characteristics can improve in-sample fit while representing momentum and size positions less fully. Reallocating shared exposures changes attribution without changing joint fitted returns. With coefficients fixed, exposure references alter holdings, trading, and subsequent risk at the same characteristic target. Statistical factor models should be evaluated not only by return fit, but also by the exposures they represent and the investment decisions they support.

We study the influence of investor attention on mutual fund investors' fund selection and fund managers' portfolio choice. Using the Google Search Volume Index to measure investor attention on individual stocks, we find fund investors tend to direct more capital to mutual funds holding more high-attention stocks; fund managers tend to perform window-dressing trading to increase the portfolio holdings of high-attention stocks displayed to investors. Our results suggest that funds, particularly those with strong incentives, strategically trade on stock attention to attract investor flows. This strategic trading behaviour is also associated with fund underperformance and leads to larger non-fundamental volatility of holding stocks.

Fluctuations in investor demand dramatically affect firms' valuation and access to capital. To quantify its real impact, we develop a dynamic investment model that endogenizes both the demand- and supply-side of capital. Strong investor demand elevates equity prices and dampens price impacts of issuance, facilitating investment and financing, while weak investor demand instead incentivizes firms to optimally repurchase shares at favorable prices, which can crowd out investment, especially among firms with liquidity constraints. We estimate the model using indirect inference by matching the endogenous relationship between investors' portfolio holdings and firm characteristics. Our estimation suggests that investor demand substantially distorts firms' real investment decisions and impedes the efficient capital allocation across firms. Eliminating excess demand reduces dispersion in the marginal product of capital by 10.74% and TFP losses by 16.20%. Investor demand also influence firm size distributions and generates a heavy right tail---large excess demand provides firms with market power and opportunities to profit from their financial market activities, contributing to the emergence of superstar firms.

Existing literature has found no evidence of market-timing ability by mutual funds using tests based on fund returns. This paper proposes alternative market-timing tests based on observed fund holdings. The holdings-based measures are shown to be more powerful than the return-based measures, and are not subject to "articial timing" bias. Applying the holdings-based tests, we nd strong evidence of mutual fund timing ability. Our findings also suggest that market-timing funds tend to have higher returns and trade more actively. Furthermore, they seem to have market-timing information beyond those common return-predictive economic variables documented in the academic studies. Finally, we quantify the potential economic value of market-timing as a contingent claim. The magnitude of the estimated values indicates that market-timing is potentially an important investment strategy deserving more academic attention.