Planetary boundary layer (PBL) Planetary boundary layer (PBL), also called atmospheric boundary layer, the region of the lower troposphere where Earthâs surface strongly influences temperature, moisture, and wind through the turbulent transfer of air mass.
Portfolio optimization tools are useful to assist planners, advisers, and clients in ways to conceptualize the asset allocation problem. But, they should not be relied upon as the primary tool for structuring an investment portfolio.
Passive management is an investing strategy that tracks a market-weighted index or portfolio. The most popular method is to mimic the performance of an externally specified index by buying an index fund. By tracking an index, an investment portfolio typically gets good diversification, low turnover, and low management fees. With low fees, an investor in such a fund would have higher returns than a similar fund with similar investments but higher management fees and/or turnover/transaction costs.